EOSC 118 - Final Exam (kill me)

Mineral Formula of Gem Corundum

Al2O3 - Al --> key to generating the colours of gem varieties - Al can be replaced by many transition elements which are common chromophores

Diagnostic Properties of Gem Corundum

- Hardness = 9 on Mohs scale - Cleavage = no dominant cleavage though sometimes has basal 'parting' and will fracture in conchoidal manner - SG = 4.0 --> HIGH; results in corundum occurring in secondary placer deposits + recoverable by panning methods - Refractive Index = 1.76 - 1.78 - Colours = all colours of rainbow --> red corundum is RUBY; blue corundum is SAPPHIRE; all other colours are FANCY SAPPHIRE - Fluorescence = some varieties fluoresce under shortwave and longwave UV if enough chromium in structure

Crystal Structure: Tourmaline

- Hexagonal (trigonal) symmetry - Euhedral crystals - ANISOTROPIC --> belongs to hexagonal-trigonal crystal system

Major Mining Activity in Canada + BC

- Highland Valley, Diavik, Sigma Mines - contributes high significant economic impact on economy BC - largest exporter of coal, leading producer of Cu, only producer of Mo - mining popular here --> easy access to global markets (ocean), low-cost electricity, integrated road + rail network, large deep-water ports - concentrated in industrial mineral mines at south end of province

Wittlesbach Diamond

- Historic blue diamond --> 17th century with Royal Family origins - 35.56 carats --> recut to 31.06 carats - Special feature: holds record for being one of most expensive auctioned diamonds

Summary of Changes in Diamond Production by Country (history)

- Historically in India - Minas Gerais in Brazil ("new world") - S. Africa (Kimberley) - Russia --> Mir Diamond Mine - Australia --> Australian Arygle Mine - Canada --> Diavik, Ekati - By 2012: majority from Africa ( Botswana, Congo, Angola, South Africa, Zimbabwe)

DIAMOND: crystal structure

- ISOMETRIC or CUBIC crystal system - 3 crystallographic axes of equal length and at 90 degrees - very strongly covalent bonded atoms in symmetrical network = hard, durable, dense material - unique because ionic bonding is more prevalent in minerals

Kimberley Process + Effectiveness

- Kimberley Process Certification Scheme (KPCS) --> monitors movement of diamonds + diamond industry to prevent conflict zone diamonds - an agreement between major diamond industry players - effective in areas that import huge volumes of diamonds (US; poverty stricken areas if they cooperate) - not effective in certain countries due to lack of regulation and smuggling --> Cote d'Ivoire, Zimbabwe, Venezuela

Pebble Deposit: Conflicts by Community + Developers

- Long history of accidents in hard rock mining --> despite promises of clean projects: affects life of Alaskans as fishing is part of their culture, life, living - Concern to environment --> accidental discharge of process chemicals, byproducts, heavy metals, acid mine drainage

Why Beryl + Corundum Display Different Colours when Cr+3 is common chromophore

- Aluminum --> majority of colour-causing b/c of Al substitution (e.g. Cr for Al = ruby; Be for AL = sapphire) - Absorption Patterns --> similar absorption patterns = same transition metal but the different absorption sites lead to diff colours

Rare Elements Commonly Concentrated in Fractionated Granitic Magma

- Be, Li, Ta, Cs, etc

Significance of PGEs throughout History

- Before 16th cent --> rare; found in Egyptian caskets - 16th cent. discovery --> Central American by Spanish; use in jewelry and only fit for a king; scarce - 17th cent --> alluvial deposits in Colombia - early 19th cent --> increase of Platinum; discovery in Russia + used in jewelry - Discovery of PGEs in Bushveld Complex, S. Africa --> changed landscape of PGEs - by 20th cent --> more available + affordable but still sometimes worth more than gold; jewelry

Pebble Deposit: Geographic Setting

- Bristol Bay region, Southwest Alaska - Home to KVICHAK + NUSHAGAK rivers --> two of most prolific salmon runs in the world - Foreign developers proposed development of world's largest open pit + underground mines at headwaters of these two rivers

Hope Ruby

- Burmese origin - 32.08 carat

Causes of Colours in Diamond

- Classification type (Type Ia, Ib, IIa, IIb) - Deformation of crystal, impurities, cation site vacancy --> vivid colours such as pink, purple, red, cognac - Natural irradiation --> green - Abundant graphite --> black - Green + red = most rare

DIAGNOSTIC PROPERTIES: Tourmaline

- Colour: diverse colour range, opaque black most common - Great features for gemstone --> TRANSPARENCY, RARITY, DURABILITY, HARDNESS - Density: 3.2 --> fairly dense but not enough for placer deposits - Cleavages: 2 POOR cleavages --> when stone breaks, it's uneven; means it's unusable for jewelry - Vertical striations down crystal face - Hardness: 7-75 - Refractive Index: ~1.61 to 1.66 - strong PLEOCHROISM - Fluoresce: in rare cases, will fluoresce under UV - A collector's fave --> range of colours, size of crystals, euhedral shape

DeBeers Diamond Monopoly

- Controlled industry since Kimberley Mine in S. Africa in 1888 - Controls movement of diamonds through Central Selling Organization, Diamond Trading Company, Sightholders and Diamond Bourses (see previous card) - Tightly moderate commodity -> keeps prices high - Diminishment of their control due to newer establishments of mines but their control continues via Kimberley Process - Impact -> competitive industry based in making money, tightly control flow to consumers, rise of synthetic diamonds

Different Gem Beryl Variety: Emerald

- Cr +3 subs for Al + 3 --> famous vibrant green colour - Generates variety of beryl known as emerald

4+1 Cs of Diamonds

- Cut and polished diamonds evaluated based on 4C system - introduced by DeBeers - fifth C recently introduced - cut, clarity, colour, carat + country of origin

Diavik Diamond Mining in NWT

- Diamonds - One of biggest in Canada

Primary Diamond Deposits

- Diamonds occur in both primary + secondary deposits - found in volcanic rocks on surface + in un-erupted magma that feed volcanoes - volcanic rocks that host diamond = KIMBERLITE or LAMPROITE

Earth as an Interconnected System

- Different parts of system: atmosphere, oceans, tectonics, deep earth, surface earth, life, etc - All aspects work together in creation and preservation of different precious materials - Each part impact and affect each other E.G. Diamonds form in deep earth, need to be brougt to surface, then natural processes move diamonds to form deposits, etc

Significance of Gold in History

- Egypt --> desirable commodity, art and treasure, wealth - Greece --> primarily financial commodity - Rome --> prized and valued gold; developed technology to find gold - Middle Ages --> not too important - Early Modern (1400-1800 AD) --> part of cultural expression in religion, politics, etc - Modern (1800 onwards) --> gold rush, economic anchor, gold standard, aesthetic appeal

FAMOUS LOCALITIES: Turquoise

- Egypt, Iran, US - Persian Turquoise from Nishapur, Iran --> best in market; running out - Egyptian deposit from antiquity but has run out - Associated with Mexico + Aztecs + NDNs

Trace elements

- Elemental constituent of mineral - found only in very small amounts - either replaces major elements in crystal structure or occupies "holes" in a crystal structure - very rarely seen in chemical formula - always reported in PARTS PER MILLION (ppm) on an element weight basis --> "10 ppm Cr" instead of "0.001461 wt% Cr2o3" - many CHROMOPHORES (elements that cause colour in minerals) often found in trace amounts

Major elements

- Elemental constituent of mineral - fundamental in mineral's crystal structure - major impact on resulting bulk properties - always part of chemical formula - always reported in WEIGHT PERCENT OF THE OXIDE e.g. Fe2SiO4 --> major element = Fe

Minor elements

- Elemental constituent of mineral - present in smaller amounts - commonly replaces major elements in minerals - sometimes part of chemical formula - usually reported in WEIGHT PERCENT OF THE OXIDE e.g. if there was a little big of magnesium in iron-dominated olivine (Fe > Mg)2SiO4 --> minor element = Mg

The role that organizations such as the GIA have in the jewellery industry

- Evaluations + training of certified gemologists --> evaluating grade of diamond - Documentations of investigated stone - Forms collective voice for industry

Why Diamonds are Rare

- FORMATIONAL ENVIRONMENT --> special geological conditoins - but actually not that rare --> 170 million carats mined annually; rarity is perpetuated through history when it WAS rare

Hooker Emerald

- Famous cut Colombian emerald - 75 carats - Set in Tiffany brooch - Smithsonian

Mogul Emerald

- Famous emerald that was shipped + carved in India - 217 carat - rectangular shape - Inscribed with Islamic text + carved with poppy flowers RMBR THE HISTORY

Different Gem Beryl Variety: Aquamarine

- Fe subs for Al --> light blue colour

RUBIES: Common Geographic Origins

- Finest quality -> Mogok Stone Tract in Burma/Myanmar - Best colour: "Pigeon's Blood Red" -> red to purple-red - Rarely larger than 5 carats

Historical Sources of Diamond (Prior to 1867)

- First appreciation in ancient India (octahedrons; euhedral shape) - 1st century BC --> mentions of diamonds in Mediterranean; mentions of diamond tools in Chinese literature - Euro history of diamonds as far back as 13th century (royal jewelry) - 17th century -> non-royal adornments of diamond - historically extremely rare - sourced only from a few alluvial (within river gravels) localities - first discovered in Golconda Region of India --> then in Brazil by 18th cent

EMERALDS: Historic Significance

- First use: decorative stones for Pharaohs - 1500 B.C. - Lower quality deposits compared to today --> "Old World" Emeralds - "Mogul Emeralds" - Similar emeralds of quality also mined in India's Rajasthan State

COMPOSITION: Peridot

- Gem variety of Olivine - Mineral Forsterite (Mg2SiO4) --> dominance of Mg over Fe - Crystallographic site of Fe and Mg in olivine group allows trace elements to enter structure --> Ni, V, Cr, Mn

Information on Diamond Grading Reports

- Grades stone + jewellery - GIA -->. main physical properties of graded diamond - Grades on COLOUR, CLARITY, CUT - not on CARAT just because that's only a quantifiable measurement (weight)

Geological Conditions for Diamond Formation

- HIGH pressure LOW temperature - diamonds stable only at great depths below surface with "cool" temperatures --> DIAMOND WINDOW (away from these pressure/temperature --> graphite) - ARCHEAN CRATONS --> old, thick rocks that push a KEEL down into upper mantle; at base of keel are favourable conditions for diamonds

Electrical + Thermal Conductivity of Diamond

- HIGH thermal conductivity --> due to covalently bonded carbon atoms - LOW electrical conductivity - this pairing is very UNUSUAL

Volcanogenic Massive Sulphide Deposits: Formation

- accounts for 99% of Canada's silver production - typically occur in lenses of polymetallic massive sulphides that form at or near seafloor in submarine volcanic environments - forms from metal-enriched fluids associated w/ seafloor hydrothermal convection - immediate host rocks: volcanic or sedimentary

Role of Gases + Volatiles in Crystallization of Pegmatites

- all pegmatites contain large amounts of gases + volatiles that are effective fluxes for pegmatite magma - fluxes = elements and/or compounds that reduce freezing point of magma - lower freezing points = more time for crystal growth - fluxing agents: H2O, F, Cl, CO3, BO3, Li, PO4

FAMOUS LOCALITIES: Lapis Lazuli

- antiquity --> egyptian + babylonian - modern --> Sar-e-sang, Afghanistan - canada has one deposit in Baffin Island

TERM: Gemstone

- any mineral highly valued for beauty, durability, rarity - usually enhanced minerals (through cutting + polishing) - most gems begin as crystals of minerals or aggregates of minerals - there are also non-mineral gemstones --> organic like pearls - there are few rocks considered gemstones - fewer than 100 minerals used as gemstones

Range of Size in Gem + Non-Gem Beryl

- aquamarine = largest size crystals in beryl family - hooker emerald = one of largest cut emeralds; 25.47 carats from colombia - guinness crystal = one of largest uncut emeralds of gem quality

"Ball and Stick" models of Crystal Structures

- atomic models of crystal structures - most common diagram to visualize unit cells - balls = atoms; sticks = bonds - PROS: useful for interpreting 3D structure of mineral - CONS: unit cells can get too complicated for this model

Trends in Diamond Pricing

- based on colour, clarity, carat size CLARITY --> jumps in prices for better coloured stones due to high demand for clean stones of good colours CARAT --> each colour category sees dramatic rise in price per carat up to ~5 carats (beyond that size it's not usually for sale)

TERM: Element

- basic building blocks of MATTER - elements composed of identical atoms - ~117 elements, each with own notation/symbol - 90% of elements occur naturally

Country of Origin

- bearing on historical significance of stone - serves as verification that it's not CONFLICT STONE

Geological Setting: Pegmatites

- beryl common in granitic pegmatites - gem varieties: aquamarine, heliodor, morganite, goshenite - concentric structure like an onion - highest quality crystals found in open space cavities or pockets of Core Zone --> large size, good transparency, colour

6 Platinum Group Elements (PGE)

- one of the precious metals less abundant than gold - Platinum (Pt), Palladium (Pd), Rhodium (Rh), Ruthenium (Ru), Osmium (Os), Iridium (Ir) - noble metal properties -- next to Ag and Au - sometimes referred to as PG Minerals - in cases of being a FINISHED PRODUCT -> PG Metals

"Large Scale" Mining

- open pit, underground, placer

Typical Grades + Sizes of PGE Deposits

- ores only need to be about 4ppm (4 g/t) of PGE to be economic

Pebble Deposit: Ecological, Cultural, and Social Significance of "downstream"

- part of their life and livelihood - environmental risks - jobs --> current sustainable fishing

Rock Cycle

- partial melting of mantle material forms magma - magma crystallizes to form igneous rocks - weathering and erosion of igneous and metamorphic rock produces sediments which lithify to form sedimentary rocks - some igneous and sedimentary rock undergo tectonic burial and metamorphism to form metamorphic rock.

Range in Size of Crystals within Pegmatites

- pegmatites consistently produce largest gemstones of any rock type

Four Main Geological Settings/Genetic Models for Gem Beryl

- pegmatitic, magmatic, metamorphic, secondary

Jadeite

- physical appearance: interlocking. blocky, granular crystals - texture: sugary and granular colours: pure jadeite = white; green (Fe); lilac (Mn, Fe); pink, brown, red, blue, black, orange, yellow (inclusions) - imperial jade --> emerald-green jadeite (chromium) - geological setting: metamorphic rocks + higher pressure settings; generally recovered in alluvial pebbles + boulders - sources: Myanmar (imperial jade), Japan, California - high value

"Polyhedral" models of Crystal Structures

- polyhedra --> common predictable shapes of cations + anions in crystalline world - PLATONIC SOLIDS --> 4 most common shapes: tetrahedron, octahedron, cube, icosahedron

TERM: Pegmatite

- premier rock type for finding large high quality gemstones - produces basically all sought after coloured gems except diamonds - pegmatite gemstones tend to occur specifically within POCKETS of pegmatite - pegmatite supply: TOURMALINE, TOPAZ, BERYL, etc - known for growing largest crystals - used as descriptor for igneous rocks with large crystal sizes

Optical Effects: Asterism

- prominent star shape that normally occurs as 6 pointed star - gemstones are best cut as "cabochons" to show this off e.g. sapphires + rubies

DIAMOND: composition

- pure CARBON - packed into dense crystalline structure - cubic symmetry - perfect octahedral cleavage

Cut

- quality of the facets that defines its proportions (not the shape of a cut gemstone) - impacts optical effects of fire and brilliance + weight of diamond - GIA rankings: excellent, very good, good, fair, poor

Volcanogenic Massive Sulphide Deposits: Size range

- ranges in size from 200k tonnes to supergiant deposits containing more than 150 million tonnes - in canada, over 350 deposits contain more than 200k tonnes

Significance of Aquamarine in History

- referenced in ancient Egypt + Greece - not as popular as emeralds - quite rare in history --> absence of large magnificent crystals diminishes its space in history and lore

Secondary Modifications of Uncut Diamond

- secondary modifications can change initial shape of any mineral through processes like corrosion or abrasion 1) after growth but DURING TRANSPORT TO EARTH'S SURFACE by kimberlite magmas - usually corrosion - rounded edges of primary crystal growths (usually octahedron) 2) DURING TRANSPORT while on EARTH'S SURFACE - usually abrasion due to ALLUVIAL TRANSPORT - strongly rounded features almost approaching shape of ball

Steps in Faceting Gemstones

-starts as EUHEDRAL CRYSTALS, BROKEN MINERAL SHARDS, WATER TUMBLED STONES - once mined --> changes hands many times before being set into jewelry (such as gem cutters and facetters) - gemstone cutting/faceting --> slow and steady grinding of precious against harder material

Important Silver Districts in Canada

1) Ag-Co-Sb veins in Cobalt, Ontario - one of the two most important veins - peak production in 1908 2) Ag-Pb-Zn veins in Elsa/Keno Hill, Yukon - discovered during klondike gold rus - gave economic boost during population decline in Yukon Other districts: - Great Slave Lake Region, NWT - Slocan District --> "Silvery Slocan" in BC - Coeur d'Alene district of Idaho - Butte, Montana

Ten Main Physical Properties of Minerals

1) COLOUR - some minerals have characteristic colours 2) LUSTRE - general appearance of its surface in reflected light - can be indicative of METALLIC or NONMETALLIC 3) STREAK - colour of powder produced when specimen drawn across surface - more consistent than colour + can distinguish between easily confused minerals 4) CLEAVAGE - ability of mineral to break along flat, planar surfaces - occurs where crystal structure has weakest atomic bonding - defined through position of crystal faces (cubic, prismatic, etc) - consistent property 5) FRACTURE - some minerals break in directions other than cleavage 6) TENACITY - used for physical properties that depends on cohesiveness between its atoms (e.g. malleability, ductility, brittleness) 7) HARDNESS - relative ease/difficulty with which it can be scratched - Mohs - extremely useful aide 8) REFRACTIVE INDEX - linked to dispersion of light into its component colours 9) SPECIFIC GRAVITY - measure of density 10) FLUORESCENCE - some minerals characterized by fluorescence - emits visible light when subject to ultraviolet - less consistent = less reliable 11) DISPERSION - related to refractive index

Methods for Creating Synthetic Diamond

1) Carbon Vapor Deposition (CVD) 2) High Pressure High Temperature Growth (HPHT)

Two Periods of Silver Mining in Canada

1) EARLY DAYS - silver extracted from thin veins of high grade ore - veins exploited by underground mining with many tunnels that chased them into depths 2) SILVER THROUGH RECOVERY AS BYPRODUCT - silver production became dominated through recovery as byproduct from mining of polymetallic deposits - more amenable to bulk mining and open pits - this is more common now

6 Discrete Phases of Mineral Resource Development

1) GEOSCIENCE - surveys to provide critical information to encourage exploration investment 2) EXPLORATION - carried out by prospectors leads to discoveries of deposits 3) DISCOVERY - depends on fieldwork, investment, and quality geoscience to bring exploration to development stage 4) DEVELOPMENT - includes feasibility, geoscience + engineering studies, raising capital + construction 5) PRODUCTION - extraction, milling, and processing to produce coal, metals, industrial minerals and aggregates 6) RECLAMATION - begins during operation and continues after closure until land is productive once again

Global Distribution of Gem Beryl

AQUAMARINE - found wherever there are pegmatites - pegmatites of Colorado, California, Idaho, Minas Gerais (brazil), Ural Mountains (Russia), Gilgit (Pakistan) EMERALD - more restricted than aquamarine --> areas where Be + Cr/V can interact - Zambia, Zimbabwe, Madagascar, Afghanistan, Brazil, Austria - Colombia --> premier locality

Common Imitations of Beryl

AQUAMARINE - not imitated due to its common-ness EMERALDS - commonly imitated - green glass; thin wafers of real emerald glued with green glass or colourless beryl - peridot or green diopside sometimes marketed as emerald

"Artisanal" Mining vs. "Small Scale" Mining

ARTISANAL --> uses manual labour; simple tools; basic recovery + processing tools SMALL SCALE --> manual labour; better mechanisation and processes both: usually for high value goods

Basic Physical Properties of Copper

AS AN ELEMENT - relatively dense - melting point: 1084C - boiling point: 2562C - reactive --> not noble element PHYSICAL PROPERTIES - good electrical and thermal conductivities - quite malleable and ductile - not a precious metal but still valuable

Native Elements

DEFINITION: - when elements occur by themselves in rock (i.e. not chemically bonded to other elements) --> NATIVE STATE - 20 elements can occur in native state not including gases -> metals, semi-metals, non-metals - considered to be MINERALS - native metals make up largest group EXAMPLE: - Au, Ag, Cu, Pt - Gold nuggets = "native gold" - Non-metallic mineral --> DIAMOND (pure C) - Native semi-metallic mineral --> ARSENIC (As)

Shape of Kimberlite Deposits

DIATREME --> vertical + carrot-shaped body - typically up to 1km across surface

Diagnostic Properties of PGEs

Density: VERY dense - Ir and Os are densest material on Earth Melting points: 1828 - 3306 Kelvin --> very high - Great chemical inertness - High resistance to corrosion - High melting points - sustained strength at high temperatures - good durability - good electrical conductivity - low thermal expansion - amazing ability to catalyze variety of chemical reactions - high melting points + durability --> hard to work with in jewelry but also makes it attractive option - purity + fineness judged on scales of 1,000 parts or .900 (3 decimal places)

Crystal Structure of Gem Beryl

Dominant Crystal Sites: - tetrahedral sites of Si and Be - octahedral sites of Al

RELATIONSHIP: Atoms, Elements, Compounds, Mixtures

ELEMENTS + ATOMS - elements composed of identical atoms ELEMENTS + COMPOUNDS - compounds form when 2+ elements join together COMPOUNDS + MIXTURES - 2+ compounds interacting NOT through chemical bonding

Local Distribution of Gem Beryl

EMERALD - Canada --> northern Cordilleran mountains of BC, Yukon, NWT AQUAMARINE + OTHER GEM BERYL - Rocky Mountains - MB, ON, QB, NWT, NS

Diagnostic Properties of Gem Beryl

Hardness: 7.5 - 8 on Mohs scale Colour: colourless when pure Cleavage: basal cleavage Fractures: conchoidal to splintery Specific gravity: ~2.6 - ~2.9 Refractive Index: 1.57 to 1.61 depending on composition Fluorescence: Long + Shortwave UV fluorescence can be observed

EMERALDS: Common Geographic Origins

Historic: - "Old World" -> Egypt presumably - "Mogul Emeralds" -> India's Rajasthan State Best emeralds today: - "New World" emeralds -> Colombia - spread through Spanish colonialization of South America

Geological Time

Humans barely exist

Geological Events to Bring Diamond from Mantle to Surface

KIMBERLITE MAGMA - main mechanism that brings diamonds upwards - generated at base of cratons + erupts in special volcanoes on Earth's surface

Lode Gold vs Placer Gold

Lode deposits --> most important domestic source in Canada (80% of historic production); a mineral deposit typically deposited by hydrothermal produces; more modern + productive too Placer deposits --> heavy minerals concentrated by gravity after being weather out of bedrock by wind or water - significance in history --> Klondike Gold Rush and panning - led to migration

Units for Mass + Purity of Precious Metals

MASS - grams, kilograms, lb - some metals measured in oz or troy oz PURITY - GOLD --> karats (purity or fineness of gold) - pure gold = 24K - % --> "100% of metal being pure" - value of 1 --> indicates pure silver (.999 silver) - scale of 1-1000 --> purity of PGMs (900 Pt = 90% pure Pt) CARAT - common unit used for weighing gemstones

Genesis of Pegmatites

PARENTAL PLUTON - commonly granite - most pegmatites will have base geochemical signature similar to their parental pluton - importance: gives rise to genesis of pegmatite FRACTIONATION - during magmatic history of granite body, may undergo significant fractionation - progressively evolved or fractionated granitic magma is eventually left - rare elements get strongly concentrated in leftover magma DYKES - when conditions are right, highly evolved magma with high concentrations of rare elements injects into overlying host rocks --> forms dykes FERTILE or BARREN MAGMA - fertile magma --> magma that generates highly factionated pregmatites - pegmatites originated from fertile granite often show geographic zoning of rare metal enrichment

Platinum Group Elements vs Platinum Group Metals vs Platinum Group Minerals

PGE - transition group of elements PGMetals - in case of finished product PGMinerals - like other noble metals, PGEs can occur as other components in other non-metal minerals

Primary Deposits

PRIMARY -> hard rock mining such as OPEN PIT or UNDERGROUND

Different Gem Corundum Varieties

PURE corundum = colourless RUBY + SAPPHIRE = vivid colours arise from elemental substitutions in Al site by transition metal elements (Fe+2, Fe+3, Ti+4, Cr+3, V+3) RUBY = Cr introduced in corundum SAPPHIRE = Fe +2 and Ti+4 substituting in structure for Al+3 - Asterisms --> star optical effect

Historically Important Ruby + Sapphire Occurrences

RUBY - Mogok region of Myanmar/Burma --> PIGEON'S BLOOD RED - Vietnamese Rubies SAPPHIRE - Sri Lanka --> Padparadscha variety - Sapphires of PAKISTAN --> KASHMIRI CORNFLOWER BLUE

Secondary Deposits

SECONDARY -> formed from primary source + concentrated in secondary location like PLACER

Simple vs Zoned vs Complex Pegmatites

SIMPLE PEGMATITES - tends to have many crystals of smaller sizes rather than small number of larger crystals ZONED PEGMATITES - different types of crystals - most significant ones come from pockets in core COMPLEX PEGMATITES - produce fantastic mineral specimens - tend to be best type for rare metal ore deposits

Local Distribution of PGEs in Canada

SUDBURY COMPLEX - canada's major supplier of PGEs - contributes significant portion of global supply

Geography of worldwide PGE Supply and Demand

SUPPLY - 5 main producing areas control worldwide geography of PGEs production - entire industry + end users are vulnerable to interruptions to supply due to this control DEMAND - Main use of Pd and Pt --> AUTOCATALYSTS (Rendering emissions less harmful for environment) - jewelry manufacturing, industrial uses, financial investments also for Pd and Pt - Rh, Ir, Ru, Os --> largely used in specialized industrial and chemical processes - Rh --> jewelry manufacturing

List of major silver ore minerals

TETRAHEDRITE + FREIBERGITE - important ores of silver - isometric system - complex crystal formulas + structures due to diverse number of elements that can be incorporated into crystals - freibergite --> Ag-rich variety ARGENTITE + ACANTHITE - high and low temperature forms of Ag2S - above 170C, isometric crystal structure of argenite = stable - below 170c, Ag2S = monoclinic crystal structure of acanthite - polymorphism + pseudomorphism POLYBASITE - less common silver ore - locally important for many mining districts - monoclinic

History of Earliest Coinage

THE LYDIANS - over 2500 years ago - first civilization to use silver + gold alloy coins -> ELECTRUM COINAGE IN CHINA - developed shortly after GREEKS, ARABS, ROMANS - coinage + coin making techniques developed quickly following the Lydians GREEK - silver tetradrachms of Athens - ~480 BC

Differences btwn Topaz Gem Varieties

TOPAZ - most common colours: colourless, light brown, blue, yellow - most rare: pink, red, orangey-red - colours generated through "colour centres" in crystal where electrons fill vacancies IMPERIAL TOPAZ - vivid reddish orange colour - most valued of varieties - originally sourced from Ural Mountains in Russia; now most from Ouro Preto in Brazil - Fine pink topaz from northern Pakistan also known

Synthetic Productions: Tourmaline, Topaz, Spodumene

TOURMALINE - can be synthesized in lab but not commonly due to abundance TOPAZ - also can be done but not common due to abundance SPODUMENE - same as above, also "semi-precious"

Common Imitations: Tourmaline, Topaz, Spodumene

TOURMALINE - most commonly imitated: paraiba-type, indicolite, rubelline tourmaline --> commands highest price - passed off as: spinel, bottle glass, amethyst TOPAZ - more commonly used to imitate other gemstones instead - sometimes mislabeled species of gem quartz like citrine, blue bottom glass sometimes used as imitation SPODUMENE - same as topaz, used to imitate other gemstones - pink and green glass, synthetic spinel or corundum

Common Treatments: Tourmaline, Topaz, Spodumene

TOURMALINE -Heat Treatment --> lighter hues, saturation, or enhance neon-blue of Cu in paraiba tourmaline - Stabilization with eproxy --> not common (emerald more common for this) - Irradiation of cut stones --> uncommon; only with pink tourmaline TOPAZ -irradiation --> colourless to blue topaz, intensifies some lighter colours -heating --> can generate pink -coating --> coated with thin film to produce optical effects + increase durability SPODUMENE - heat treatment --> eliminate undesired effects; vivifies faint greens and pinks

Main Variables to Value: Tourmaline, Topaz, Spodumene

TOURMALINE -semi precious -worth less than emeralds, rubies, sapphires; rarest colours can be worth as much tho -variable in colour --> hard to value -clean of inclusions (unless super rare colour) -paraiba tourmaline worth the most (rarest) TOPAZ -not too high value on common varieties -imperial topaz go for 1000 usd /carat for larger stones - even rare pink/red topaz goes up to 3500 usd, but rarely alrger than 5-6 carats SPODUMENE -good hiddenite is rarer than kunzite --> typically goes to collectors -kunzite and lower grades are fairly common

TERM: Rock

naturally occurring aggregates of minerals

TERM: Grade

or concentration - describes richness of ore - often reported as weight of commodity "per ton of rock"

Corrosion in Pegmatites

DEFINITION - early minerals corrode and replaced with minerals of similar composition (e.g. spodumene -> lepidolite) WHY IT OCCURS - abundance of volatiles with highly fractionated magmas can be detrimental to early life minerals in pegmatites - geochemical environments created can be corrosive to minerals

8 Most Abundant Elements in Earth's Crust

Most to Least Abundant: - oxygen (O) - silicon (Si) - aluminum (Al) - iron (Fe) - calcium (Ca) - sodium (Na) - potassium (K) - magnesium (Mg)

List of common copper ore minerals

NATIVE FORM - can occur in native form - isometric (cubic) crystal system - soft --> low hardness - ductile - typical copper colour COPPER SULFIDE or COPPER CARBONATE - most important copper minerals belong to sulfide group --> Chalcocite, bornite, chalcopyrite, covellite - other non-important non-sulfide copper ore minerals --> cuprite, azurite, malachite

Basic structure and habit of crystalline silver

NATIVE SILVER - isometric crystal system - commonly occurs as wiry or dendritic crystals with metallic lustre

Ranges in Size of Gem and Non-Gem Corundum

NON GEM - opaque non-gem --> can be found GIANT - huge crystals - largest corundum found to date = 335 lbs GEM CORUNDUM - can still reach impressive sizes (but not up to 300 lbs) - faceted stones tend to be smaller than those shaped into cabochons --> done for star rubies + star sapphires

Burmese Ruby

- "The Graff Ruby" - 8.62 carats

Optical Effects: Chatoyancy

- "cat's eye" effect - result of many fine fibre inclusions oriented in parallel manner - often cut as cabochons

3 Main Geological Time Periods for Gold Deposits in Canada

- 2800 to 2500 million years ago - 2100 to 1800 Ma - 600 to 50 Ma - corresponds with major periods of CONTINENTAL ACCRETION -OROGENIC --> 2740 to 2620 Ma -INTRUSION-RELATED --> Archean (2700 Ma) -EPITHERMAL --> last 50 Ma

The Cullinan Diamond

- 3106 carats - Largest diamond rough ever found - Yielded 9 significant stones --> British Crown Jewels

Dresden Green Diamond

- 41 carats - Naturally green --> rarest in diamonds - Sits in "Green Vaults" in Dresden - Originates from India too.

Richard Burton Ruby

- 8.24 carats - Elizabeth Taylor collection

TERM: Proton

- = Atomic Number ( # of protons it has) - POSITIVE electric charge - located in NUCLEUS - atomic forces keep NEUTRONS + PROTONS packed together

Mogok Ruby

- AKA Alan Caplan Ruby - 15.97 carats - One of finest cut rubies

Optical Effects: Iridiscence

- AKA opalescence - play of colour from internal scattering of light off of fine particles in a mineral - sometimes describe as "schiller" - commonly seen in sunstone + opals

Concept of Charge Neutrality w/ other Minerals

- All compounds (including minerals) must be CHARGE NEUTRAL - every positive charge balanced with negative charge (anions and cations) - Importance: understanding elemental substitutions of minor + trace elements

Common Tools used by Gemologists to discern properties

- Loupe (handheld magnifier) - Chelsea Filter/Emerald Filter (colour filter to discern what range of colours are seen thru filter) - Dichroscope (determining optic class; capitalizes on optical effects) - UV lamp (used to observe fluorescence) - Refractometers (used to determine refractive index) - Diamond testers - Microscope - Spectroscope - Pocket + Benchtop Models -> used to differentiate specific stones from one another - Immersion Cells or RI Liquids --> determines refractive index - Polariscope --> sophisticated benchtop dichroscopes

Volcanogenic Massive Sulphide Deposits: Major Elements Found

- Major sources of: Zu, Cu, Pb, Ag, Au - Significant sources of: Co, Sn, Se, Mn, Cd, In, Bi, Te, Ga, Ge, As, Sb, Hg

Summary of DeBeers Group

- Mined majority of diamonds and controlled flow to consumers --> control over production and sale - Kimberley Process - rise of competitors changed the way diamonds polished, mined, sold --> ethical

Black Prince Ruby

- Most famous ruby - Set in Crown - Red spinel --> not ruby - Originated from Spain

TERM: Anion

- NEGATIVELY charged ions - ions has to do with valence charge + exchange of electrons

Gold: Diagnostic Properties

- Occurs naturally in NATIVE FORM -> gold can be a MINERAL - considered a NOBLE METAL --> inert, will combine with other elements to form rare material - considered a METAL after processing --> can be alloyed or mixed with other metals to produce various effects (like diff colour and density) - as an ELEMENTt - transition elements - PHYSICAL PROPERTIES - density: 19.3 g/cm^3 - melting point: 1064C - boiling point: 2808C - resistance to corrosion + conducts heat and elecricity - malleable MINERAL - low hardness: 2.5 - colour: golden yellow

Koh-I-Noor Diamond

- One of largest diamonds - Centrepiece in QE's crown - From India probs - Original form isn't documented, but modern form is - Used "crystallogenic analysis" to determine features, orientation, and genealogy - Used to create perfect replica from cubic zirconia REMEMBER ITS HISTORY

Patricia Emerald

- One of largest uncut fine Colombian emeralds - 632 carats (126 grams) - 6.35 cm long + 2.54 cm wide - American Museum of Natural History

General Economic Significance of Lode Gold Deposits in Canada

- Orogenic supplies 80% of Canada's historic Au production - attracted many exploration dollars to Canada - important role in economic infrastructure in mining + exploration - adds new avenues of exploration of other mineral deposit types

TERM: Cation

- POSITIVELY charged ions - ions are charged atoms

Common Tools used by Mineralogists to study properties

- Polarizing Microscope --> study origin of rocks - Raman Microscope --> scattered light imparts gemstone's diagnostic patterns - Electron Microphone or X-Ray Difractometer --> determines precise crystallographic structures

Basic + Distinct Properties of Metals

- Primary native metals: GOLD, SILVER, COPPER, PLATINUM - good electrical conductivity - good thermal conductivity - high densities - malleability - ductility - metallic luster

Winston Legacy

- Recent example of legendary diamond - Flawless - D-Colour --> i.e. colourless - 101.73 carats

Historical use + appreciation of gems and precious metals

- Religion - Symbols of power -> wealth - Amulets to tap into mystical properties - Royal gifts + official seals - Used as currencies + financial investments (diamonds + gold) - Intrinsic beauty and properties (like gold not corroding + being malleable)

Cut Diamond Shapes

- Round Brilliant --> classic shape - Heart and Arrows; Amore; Arctic Empress; Star Cut - Varied cuts --> designed to maximize brilliance + fire or designed to maximize colour

Current use + appreciation of gems and precious metals

- Same as historic principles - Less restricted to just wealthy tho (but like..not by much imo) --> increased demand led to increased production led to lower prices - Used as international standards i.e. currency

Influence of celebrity jewellery style and arts and design competition

- Showcases best artists and raises profile for certain aspects of gem/jewelry industry - Effective avenue for marketing - Worn on Red Carpet, for eg. Example of competitions: AuDITION (gold), "Gold Inspirations" (Website), The American Gem Trade Association (well known in N. America)

Hope Diamond

- Special features: deep blue colouration and lack of internal flaws - 45.52 carats - Shows VS1 Clarity - Cut: Cushion Antique Brilliant - Mined from India, sold to King Louis XIV these imperialist f*ckers - Sits in Smithsonian

General Geography of Gold Supply + Demand

- TOP PRODUCERS - China, Australia, Russia, South Africa, Peru, the US - Canada was 6th largest producer - TOTAL GOLD - ~3150 t

Common Tools used by Geoscientists to investigate rock + mineral properties

- Unaided Eye - Tweezers - Hammers + Chopsticks - Scratch Pad + Hardness Picks

TERM: Gangue

- a component of veins - includes minerals of no economic interest - usually consists of quartz, pyrite, calcite

TERM: Ore

- a component of veins - includes the metal bearing minerals of economic interest

COMPOSITION: Lapis Lazuli

- a mixture of minerals --> lazurite, pyrite, calcite, minor diopside, sodalite, and hauyne

6 Crystal Systems

- according to maximum symmetry of their faces 1) CUBIC - 3 crystallographic axes at right angles - of equal length 2) TETRAGONAL - 3 crystallographic axes at right angles - only two are equal in length 3) HEXAGONAL + TRIGONAL - 3 crystallographic axes set at 120 degrees - equal length - a fourth axes that's perpendicular to the 3 4) MONOCLINIC - 3 crystallographic axes, 1 at right angle - unequal length 5) ORTHORHOMBIC - 3 crystallographic axes at right angles - of unequal length 6) TRICLINIC - 3 crystallographic axes at angles less than 90 degrees - of all unequal length - least symmetrical shape

Geological Setting: Secondary

- beryl resistant to weathering + has high hardness; not dense 1) eluvials --> rocks + minerals will weather away, but the "residuals" will remain unweathered + concentrated 2) colluvial --> fan of crystals or rocks migrating down a hillside away from primary source hosted in bedrock 3) alluvial --> classic secondary deposit; flowing water moves lower density materials and the densest material gets left behind in bends or hollow depressions (placer deposits)

Rarity of Gem Beryl

- beryllium --> very little berylliums in upper continental crust; concentrates only in specific rock types such as granites and pegmatites - aquamarine --> more abundant due to Fe (chromophore) found in most settings - emeralds --> Cr and V also required; rarer - classic emerald model --> requires Be to interact with Cr - red beryl + dark blue beryl --> most rare

PROPERTIES: Lapis Lazuli

- blue colouration --> from lazurite, sodalite, hauyne

RELATIONSHIP: Rock + Minerals

- both NATURAL -> not made in lab or elsewhere - rocks are aggregations of minerals

TERM: Colour

- brain's interpretation from the incidence of light - colour of an object is our eye's interpretation of light + visible range it interacts with

Local Distribution of Gem Corundum

- canada doesn't produce commercial corundum - handful of gem localities - Beluga Sapphire Occurrence --> most developed gem corundum project on Baffin Island - BC source of 6-star sapphire

Chemistry + Mineralogy

- chemistry at root of mineralogy - understanding how minerals are classified + formed - provides basis for correlating rocks + minerals - naturally occurring vs. synthetic crystals

Different Gem Beryl Variety: Beryl

- closely tied to substitution into octahedral sites of Al-occupied sites

Subtractive Colour Theory + Colour in Minerals/Gemstones

- colour of gemstone in balanced white light is result of absorption + transmissions of certain wavelengths of electromagnetic radiation by gemstone - the colours we see are complementary to the colours that are absorbed in the theory - if blue-violet light is absorbed --> resulting wavelengths that are transmitted produce yellow colour, as interpreted by our eyes - think of colour wheel - helps understand generation + perception of colour in gemstones

DIAGNOSTIC PROPERTIES: Spodumene

- colours: typically colourless --> light pink kunzite uncommon; vivid green hiddenite very rare - forms prismatic crystals with roughly square + rectangular outlines - cleavages: 2 distinct cleavages running parallel to c-axis + intersect at 90 degrees - hardness: 6.5 - 7 - specific gravity: ~3.2 --> moderate -RI: 1.66 to 1.68 - fluorescence: commonly fluoresces under short + long wave UV - can be quite large - spodumene historically mined for Li content

Crystal Habits

- complete desc. of external shape of crystal - all of crystal's visible characters CRYSTAL FACES - prism, prismatic, pyramidal CRYSTAL FORMS - cubic, dodecahedral, dodecahedrons, rhombohedral AGGREGATES - granular, fibrous, radiating, botryoidal, stalactitic, concentric, geode, oolitic, massive CRYSTAL APPEARANCE - tabular, bladed, stalactitic

COMPOSITION: Turquoise

- complex Cu - Al phosphate mineral - forms in microcrystalline masses with other accessory materials - deposits form near Cu-bearing intrusive rocks due to surface waters interacting with Cu-rich rocks

MINERAL FORMULA: Tourmaline

- complex borosilicate mineral group --> known for being a "garbage bag" because so many different elements can enter structure - BASE formula --> XY3Z6(BO3)3Si6O18(OH)4 (XYZ represents crystallographic sites with variable composition) - base SCHORL formula (most common variety) --> NaFe3Al6(BO3)3Si6O18(OH4) (X = Na, Y = Fe, Z = Al)

"Fair Trade" - Gems, Metals, Jewelry

- concerns over country of origin and path it took to consumer - avoiding exploitation of illicit/irresponsible exploitation of resources 1) environmental protection 2) fair labour conditions + worker rights 3) product integrity 4) cultural appreciation 5) supply chain transparency 6) fair value 7) full information for consumers

Physical Morphology of Zoned Gem-Bearing Pegmatites

- consists of CORE zone surrounded by distinct zones moving outwards towards CORE MARGIN, INTERMEDIATE ZONE, WALL ZONE, BORDER ZONE

3 Common Ways to Report Mineral's Composition

- conveys same elemental content in different formats e.g. SiO2 (1 atom of Si, 2 atoms of O) 1) ATOM BASIS --> 33% Si and 66% O per formula unit (1 Si for every 3 total atoms) 2) ATOMIC WEIGHT BASIS --> Si contributes 46% while O contributes 54% of atomic weight - Si (28 amu) + O (16 amu x 2) = 60 amu 3) OXIDE WEIGHT BASIS - reporting composition of quartz based on weight % of oxides - the WEIGHT PERCENT of Si oxide in quartz is 100% (SiO2 only has oxide in quartz) - compared to Fe2SiO4 (u would then need to consider FeO and SiO)

Significance of Copper throughout History

- copper and its alloys (brass and bronze) vaulted civilizations from stone to bronze age - used in primitive tools, investment casting of ceremonial objects, use as wiring to conduct electricity

Significance of Emerald in History

- coveted in ancient Greece - mentioned in the Bible (belonged to Lucifer) - coveted in ancient India - ancient Aztec used in jewelry + ceremonial items

Difficulties + Opportunities w/ Artisanal + Small Scale Mining

- dangerous practices - little regard for health + safety - child labour - usually driven by poverty --> but have higher economic and social significance - sometimes has negative impact on environment - livelihood strategy adopted by rural/small villages --> but large companies see miners as "trespassers"

TERM: Atomic Mass

- defined by TOTAL number of PROTONS + NEUTRONS - measured by ATOMIC MASS UNITS (amu) - protons + neutrons = ~1 amu - Au = 196.967 amu - Importance: as amu increases, so does density of material that atom is in

TERM: Critical Angle

- defines the angle of incidence of internal reflection - value of critical angle dependent on refractive index of gemstone + surrounding materials

Secondary Diamond Deposits

- diamonds moved from primary source + concentrated in new location - rivers + nearshores currents

Cause of Diff. Colours in Gold Alloys

- different from how other crystals gain their colours (via crystal field theory) - optical effects --> due to how atoms are chemically bonded + movements of electrons within metallic medium - metallic minerals (gold, silver, copper) held together through METALLIC BONDING, not ionic like most gemstones - re-emittance through BAND THEORY --> gives rise to different hues in materials with metallic lustre (or else it'd all be greyish-white) - Alloying = mixing of different metals on atomic scale -> results in colour + diff physical properties

Effects of Illumination Types on Colour

- different sources of energy will emit electromagnetic radiation at diff. intensities across the spectrum - e.g. LED, natural daylight, incandescent (tungsten), etc - used to optimize conditions in jewelry salesrooms

Significance of Diamond Discovery in South Africa (1867)

- discovery of diamond-bearing KIMBERLITE at Kimberley, S. Africa in 1867 --> diamonds much more common, no longer royalty only - originally claims over mine were disputed before establishment/monopoly of DeBeers (1888)

Crystal Structure of Corundum

- each Al atom in crystal bonds with 6 O atoms in form of OCTAHEDRON - ball and stick model more common due to its structure

Significance of Silver through History

- earliest uses --> Egyptians, the Americas - 4 significant stages in history -> OLD WORLD SILVER (4000 BC -1500 BC) - most ancient use of silver; decorative + functional purposes NEW WORLD SILVER (1500 -1875) - discovery of silver in Americas by Spanish - rich mines est. in Mexico, Peru, Bolivia dominated market RISE OF NORTH AMERICA (1876 - 1920) - discovery of Comstock Lode in Nevada - encouraged technological advances MODERN ERA (1921 - Present) - globalized silver production - silver mining --> exploitation of resources - advanced technology

Gota de Aceite Optical Effect

- emeralds of finest quality = Gota de Aceite

Pebble Deposit: Economic Significance

- estimated value of over $300 billion

FAMOUS LOCALITIES: Ammolite

- exclusively produced in Canada - discovered near Lethbridge

DIAGNOSTIC PROPERTIES: Topaz

- forms PRISMATIC CRYSTALS with 8 sided cross-section (like lozenge) terminated in wedge-like fashion - striations are common along length - cleavage: perfect basal cleavage --> difficult for jewelry - hardness: 8 --> above tourmaline + quartz, below corundum - dense: SG of ~3.5; fairly dense - can be quite large

Crystalline Gold: Basic Structure and Habit

- forms as intricate mineral intergrowths with no prominent crystal faces - will grow occasionally as intricate euhedral crystals or in dendritic patterns

Geological Model: Xenocrysts in Alkali Basalts + Lamprophyres

- forms at great depths below the continents in upper mantle - xenocrysts = when crystals become entrained in magma, such as alkali basalts and lamprophyres - corundum window

Global Distribution of Gem Corundum

- found everywhere - heat treatment expanded range from which gem varieties can be sourced - most important historical deposits --> Sri Lanka & Kashmir (premiere sapphires), Burma & Thailand (rubies)

COMPOSITION: Ammolite

- gemstone ammolite is fossil shell of Upper Cretaceous ammonite --> ORGANIC gemstone ish - fossilization of ammonite happens gradually with sedimentary formation --> by transforming into mineral aragonite - thickness of aragonite layers produce diff colours --> THICKER = red and blue; THINNER = blue and violet

Rarity of Gem-Bearing Pegmatites

- geological environment --> requires relatively abundant granitic rocks - high volatile concentrations --> necessary to facilitate growth or crystals, but can cause corrosion - slow and steady work of erosion --> required to remove enough overlying rock

Mineral resource vs. Mineral reserve

- geologist labelling how much ore is present in an ore deposit - MINERAL RESOURCE --> if there are enough results to roughly quantify amount of ore in ground (the resource) - MINERAL RESERVE --> requires detailed economic considerations (electricity, equipment, etc); resource to reserve

Communities and Small Scale Mining (CASM) Organization

- global networking + coordinating facility - works to reduce poverty by improving conditions in developing countries

Differences of Grades + Tonnages btwn Ore Deposits for Diff. Commodities

- gold ore deposits resported in ounces or grams per Au per ton of rock - diamond ore deposits often reported in carats of diamond per ton (or hundred tons) of rock

Colour

- important variable for consumers - ideally: colourless - all diamonds affected by yellow tinge - GIA rankings: D (colourless) to Z (fairly deep-coloured yellow; undesirable)

TERM: Vein

- infillings of fractures by minerals - veins have two components: ore and gangue - veins can host rich enough silver or gold to mine

Clarity

- internal and external imperfections of a stone - internal flaws: solid mineral inclusions; fluid-filled inclusions; clouds; feathers - external flaws: scratches; abrasions; burns - GIA grading for clarity: I (included) to FL (flawless)

Modern uses of PGEs

- jewelry --> durability and strength, retains white colour, hypoallergenic; alloys used in jewelry - autocatalysts - scientific experiments - machinery - electronics, coating material

"Small Scale" Mining

- labour intensive - employs higher level of mechanisation and sophisticated processes compared to "artisanal" - most commonly undertaken on highly valued goods --> diamonds, coloured gemstones, gold, other industrial minerals + consumables

Behaviour of Light (Electromagnetic Radiation) as a Wave

- light = electromagnetic radiation - light behaves like a wave --> distance from peak to peak - light can be described by its wavelength - for gemstones, interaction with light best described using wave-like approach

RELATIONSHIP: colour + wavelength of light

- light in the visible spectrum is composed of colours (or wavelengths) in visible part of electromagnetic spectrum - ROY G BIV in visible portion of spectrum - UV (shorter range of wavelength) and NIR [near infrared] at longer wavelengths

Silver: Diagnostic Properties

- like gold, silver is an element that occurs naturally in NATIVE FORM - solid metal at room temperature as well and exhibits similar properties (malleability + conductivity) - occurs naturally as alloys (like Au + Cu) - Density: 10.5 g/cm^3 --> dense but less dense than gold - Melting point: 961C - Boiling point: 2212C - Extremely high electrical + thermal conductivity (like gold) - Prone to tarnishing (unlike gold) - Much more reactive --> not a noble metal MINERAL - NATIVE SILVER - low hardness ~2.5 ELEMENT - transition element

Diamond Development Initiative (DDI)

- made to address problems of unregulated small-scale mining - collaboration of NGOs, govts, and private sector - complements Kimberley Process - focuses on development of communities involved in small-scale diamond mining - designed to contribute to UN's development goals (e.g. eradicate poverty)

Differences btwn Spodumene Gem Varieties

- main gem varieties: KUNZITE + HIDDENITE (some yellow produced too tho - TRIPHANE) - HIDDENITE --> has Cr as its chromophore LIKE EMERALD; green; Hiddenite, NC, USA or Kabul region of Afghanistan -KUNZITE --> like morganite, colour comes from trace Mn -more common than hiddenite - found everywhere in world -famous localities --> Minas Gerais, Kabul region - RARE COLOURS --> hues of both pink and green; polarizing filters used to observe pleochroism

Geological Model: Secondary Accumulation in Placers

- major source of gem material - corundum first formed in primary setting ( marble or alkali basalt) --> concentrated in more spatially restricted environment through processes of weathering + erosion - corundum has higher specific gravity = tends to settle at base of alluvial systems like gold

Importance of Total Internal Reflection (wrt shape of cut of gemstone)

- maximize brilliance of stone achieved in DIAMONDS --> when much of light enters crown facets reflects lower pavilion facets, then re-emerges through crown to our eyes

TERM: Refractive Index

- measure of how much a medium will refract light of specific wavelength passing from vacuum into the medium - used as diagnostic features in identifying gemstones + minerals

Pebble Deposit: Geological Significance

- mine backers claim there is a massive copper deposit, as well as gold and molybdenum ever discovered - known mineral resource to support life-long mine

TERM: Pleochroism

- minerals that display different colours depending on crystallographic direction - best viewed through DICHROSCOPEs - example: tanzanite (brown, purple, blue)

Nephrite

- more common + widespread than jadeite - structurally identical to jadeite (both calcium magnesium silicate hydroxides) - colours: less colour variety than jadeite; dark green (Fe); cream coloured (Mg); white (pure tremolite - "mutton-fat jade") - structure: more fibrous - textures: silky and fibrous (because of amphiboule) - geological setting: lower pressure origins - physical appearance: tightly interlocking fibres --> stone tougher than steel - use: used for tools, most commonly found in China + NZ

Primary Morphology of Diamond

- most common habit: octahedron (cubes also common)

RELATIONSHIP: Minerals + Gemstones

- most gems are minerals - this allows us to differentiate a valued gemstone from common red glass

Basic Structure + Habit of crystalline PGMs

- most have native metal PGE minerals (Pt, Pd, Ir, Rh) belong to isometric crystal system - Os and Rh, when isolated and pure --> hexagonal crystal class - single crystals are rare, but when found they're in form of interpenetrating cubes and less commonly octahedrons

TERM: Electron

- much smaller than neutrons and protons - NEGATIVE electric charge - located OUTSIDE nucleus in atom - orbits atomic core in ELECTRON CLOUD that's larger than nucleus - doesn't contribute much to atomic mass

TERM: Mineral

- naturally occurring - homogeneous solid with definite chemical composition + crystalline structure - usually formed by inorganic processes

Main Variables in Valuing Gem Beryl

- non-emerald gem beryl --> free of inclusions; "eye-clean" EMERALDS - intensity + saturation of colour it exhibits - depends on cut, clarity, hue, colour, brilliance, polish, origin, treatment of given stone

PROPERTIES: Alexandrite

- normally light brown or golden brown - colour change properties --> vivid emerald green in DAYLIGHT; purple-red in INCANDESCENT lighting - due to large absorption band centered in yellow region as a result of Cr content - STRONG PLEOCHROISM

TERM: Reflection

- obeys simple geometrical law --> angle of incidence = to angle of reflection - when light passing through medium strikes another medium --> part of light is reflected

Elemental Substitution

- occurs in minerals and very important for gemstones - common for minor elements to sub in for major elements -

PROPERTIES: Peridot

- occurs in rocks called peridotite or dunite - "Pallistic Peridot" --> interesting type of peridot - originates from meteorites called "pallistic" --> extraterrestial gemstone - yellowish-green but shares many of the same properties

Synthetic Productions of Corundum

- often produced synthetically 1) Czochralski's Drawing Method - all colours can be produced synthetically with large sizes --> rod with small corundum seed crystal lowered into molten material + slowly removed 2) Vernueil Process --> 'dripping' melted corundum onto bulb shaped corundum crystal

Determining Metal Content of Deposit

- once you have tonnage + grade of deposit --> calculate total mineral/metal content - theoretically: multiply GRADE x TONNAGE = TOTAL METAL CONTENT

Open Pit Mining

- one of the main mining methods of mining HARD ROCK ("primary") ore deposits - a large hole is mined + material extracted - often used when mineral deposit close to surface and extensive in size - much more cost effective

Underground Mining

- one of the main mining methods of mining HARD ROCK ("primary") ore deposits - for ore deposits not close to surface + have complex geological geometries - network of underground ramps and tunnels

Placer Mining

- secondary ore deposits mining - formed from commodity that was eroded from primary source + concentrated in secondary location above bedrock - gold originates from primary hard rock source + is transported via streams/rivers before settling - minerals with high density can work their way deeper in layers of sediments + end up on top of solid bedrock at base of river gravels e.g. gold, diamond --> alluvial deposits - targets of gold rushes - use picks, shovels, tools --> panning - heavily regulated because of environmental impact

Optical Effects: Labradorescence

- similar to irisdiscence - caused by diffraction of light interacting with very thin layers of calcium + sodium feldspar - most commonly seen in labradorite

Geological Setting: Metamorphic

- similar to magmatic --> source-transport-deposition - metamorphic-hydrothermal submodel - the most famous + valuable deposits follow the metamorphic-hydrothermal model --> emeralds in Colombia

3 States of Matter

- solids, liquids, gas MINERALS + MATTERS - these are solids - sometimes passes through liquid state en route to being refined in purer form - gold recovered from rock as solid, melted into liquid when collected, then converted back into solid gold (can also exist as gas)

TERM: Numismatics

- systematic study of currency - modern discipline is divided into 3 parts --> 1) coins 2) paper money 3) non-traditional currencies - may also consider stocks and bonds as another part - studies both ancient and current currencies from economical, historical, and social aspects

"Alternative" metals entering jewelry industry

- tends to be cheaper - Tungsten Carbide --> popular due to hardness - Titanium (Ti) --> durable; marketed for men like Tung Carb - Stainless steel and aluminum --> very accessible but too common and less robust compared to the other two options

Carving/Cutting "en cabochon"

- these crystals not often appropriate for faceting, so they're carved en cabochon instead - typically shows vibrant colours or interesting textures valued in antiquity (e.g. lapis lazuli or jade)

Carat

- total weight of stone measured in carats - larger the stone = the more valuable

Brass vs. Bronze

- two most important alloys of copper BRASS - copper-zinc alloys - bright yellow colour BRONZE - copper alloys commonly with tin - have duller lustre

TERM: Mixture

- two or more COMPOUNDS that join together but NOT through chemical bonding - ROCKS are bulk mixtures of minerals head together through interlocking physical network of mineral grains

PROPERTIES: Ammolite

- two types of ammolite have different microstructures 1) type 1 (Fracture) --> more common, shingle-like, more competent 2) Type 2 (sheet) --> more desirable and rare, sheet-like, not as common and requires stabilization before use in jewelry

PROPERTIES: Turquoise

- used throughout antiquity as valuable carving and cabochon stone - colours: range from green to blue; most prized = medium sky blue - texture: little texture of matrix present = most valued

Significance of Jewelry Throughout History

- used to adorn human for millennia - development of technology has revolutionised metalsmithing over and over again - but the fundamentals of working with precious metals + stones remain - origin of gemstone faceting --> cabochons and carvings

COMPOSITION: Alexandrite

- very valuable Cr-bearing variety of chrysoberyl

TERM: Tonnage

- volume of ore body = tonnage, or total number of tons (unit symbol = t) of ore within deposit - often in units of millions of tons (Mt)

TERM: Compound

- when TWO or MORE elements join together - elements combine through CHEMICAL BONDS - compounds represented through CHEMICAL FORMULAS - most GEMSTONES/MINERALS are COMPOUNDS

TERM: Refraction

- when light passes into one medium to another, its speed changes causing light to "bend" or change

TERM: Total Internal Reflection

- when light travels from medium with high refractive index (gemstones) to one with low refractive index - important in gemstones wrt maximizing brilliance of stones

TERM: Dispersion

- when white light enters or leaves a material at angles other than 90 degrees - is what gives gemstones their fire

Local Distribution of Important Gem-Bearing Pegmatite Districts

- young Cordilleran in Western Canada (BC, Yukon, NWT), Canadian Shield, eastern Appalachian - no large gem quality stones produced in Canada

TERM: Neutron

- ~equal number of neutrons as protons in atom - NO ELECTRIC charge - located in NUCLEUS - atomic forces keep NEUTRONS + PROTONS together

Four Modern Techniques in Jewelry Making

1) HOLLOWWARE AND STAMPING - attractive alternatives to the core techniques b/c it reduces overall cost of jewelry making 2) ELECTROFORMING - process of applying thin layer of gold onto performed object - reduces cost, easier to fabricate - rhodium used for electroplating to whiten Au-Ag white gold alloy 3) MODERN DESIGNING - technological + computer advances revolutionizing manufacture and production taking place - Computer Aided Design (CAD) Software, Computer Aided Manufacturing 4) MODERN HIGH THROUGHPUT PRODUCTION - GIA ties together steps of cutting, casting, stamping - not presentative of industry as a whole

Common Diamond Treatments

1) HPHT Annealing - High pressure, High temperature - most common - removes brown body colour, removes or enhances yellow colour, produces other colours after removing brown 2) LPHT Annealing - Low pressure, High temperature - chosen for highly-flawed stones with numerous inclusions - produces overall black/dark appearance to hide imperfections 3) Irradiation - creates VACANCIES within atomic lattice of diamond can combo all three: HPHT + irradiation most common pairing - Other treatments not for colour but CLARITY - glass-filling; laser-drilling; acid-boiling

Three Main Mechanisms of Colour Generation in Gems

1) IDIOCHROMATIC MINERALS - self-coloured from essential constituent - inherent colours that come from their element components e.g. peridot (Fe2SiO4) --> Fe is chromophore 2) ALLOCHROMATIC MINERALS - "other-coloured" from impurity - no inherent colours --> requires impurities to generate colours e.g. Emerald (Be3Al2Si6O18) --> Cr is impurity that acts as chromophore 3) PSEUDOCHROMATIC MINERALS - "false-coloured" from physical optics - shows colours through dispersion + scattering of light - optical effects of scattering: asterism; chatoyancy; iridiscence; opalescence; labadorescence e.g. Diamond (C) --> colour or "fire" gained through dispersion

Common Treatments of Beryl

1) OILING -most common -fills stone's air spaces --> appears less flawed 2) POLYMERS -improves clarity -adds durability 3) EPOXIES -repaired using epoxies if breakage occurs in stone 4) HEAT -heat treated to bring out the blue in mediocre-coloured rough beryl -resulted in abundance of aquamarine in market

Scientific Method

1) Observations 2) Hypothesis 3) Test hypothesis 4) Repeated testing --> creates theory 5) Law --> is theory repeatedly happens, becomes Law 6) Continual re-examination --> laws can be reinterpreted

Most common geological settings of copper ores

1) PORPHYRY DEPOSITS - significance of porphyry deposits in Canada + world (~50% in Canada) - Bingham Canyon Copper Mine (Utah) - Grasberg Open Pit (Indonesia) - Highland Valley Copper Mine (BC) 2) Ni-Cu Deposits of Sudbury (~29%) 3) VMS Deposits across country (~21%)

5 Main Groups of Transparency

1) Transparent 2) Semi-transparent 3) Translucent 4) Semi-translucent 5) Opaque

Two Properties for Elemental Substitution

1) if the cations of the two elements are similar (similar charge) 2) if the ionic radius is similar (the goldilocks principle)

3 Main Geological/Genetic Models for Gem 1Corundum

1) primary metamorphic corundum in gneisses and marbles 2) xenocrysts in akali basalts + lamprophyres 3) secondary accumulation in placers

The steps involved in bringing a diamond to market:

1. Geological prospection, exploration and development of mine site ○ Diamonds are found through exploration and mined from the ground 2. Production of rough diamonds from mine(s) go to the Central Selling Organization ○ Sorted into gem, near-gem, and non-gem parcels by the Central Selling Organization 3. Sorting, valuing, and sighting of rough stones by DTC to Sightholders ○ The Diamond Trading Company coordinates delivery of raw goods into optimized parcels for the Sightholders. ○ These parcels are divided based on size, colour, and clarity of the rough diamonds ○ These parcels are called "sights" ○ Their sales are tightly monitored-- only registered Sightholders are normally allowed to purchase sights 4. Cutting and polishing into finished diamonds ○ Once the parcels are bought, the rough diamonds are then faceted and transformed into what consumers usually encountered -> polished gemstones ○ There are a number of 'cutting houses' in the world § Some of the historical centers: in Antwerp, Mumbai, New York, Johannesburg § Lower cost cutting facilities have become more common □ Located in places like: India, Thailand, China 5. Jewellery and gem manufacturing and distribution ○ Jewellery manufacturing happens on both large and small scales ○ Some of the larger retail outlets have own manufacturing arms ○ Most retail outlets are 'independents' - source finished products from manufacturers around the globe ○ Each manufacturer has specific target clientele in which they design jewellery for § e.g. middle class consumers or high end luxury brands 6. Retail stores and sales ○ Eventually diamond jewellery (and sometimes loose diamonds) makes way to jewellery retailers The end consumer then have opportunity to purchase

Geological Setting: Magmatics

2 general modes of magmatic production of beryl: 1) in situ --> Beryl grows within an intrusive body without being concentrated in any one place from granitic magma; usually aquamarine 2) hydrothermal fluids --> very hot waters with amounts of dissolved elements that can be transported distances from original source - MOST IMPORTANT model for gem beryl formation - interaction with host rocks cause corrosion = formation of diff. gem beryl varieties if includes chromophores - forms emerald e.g. super rare Red Beryl in Wah Wah Mountains, Utah

Main Valuables in Valuing Gem Corundum

4 + 1 Cs 1) colour --> most important 2) clarity 3) origin 4) size --> larger = rarer 5) cut

4 Pegmatite Groups + Prospective for Gemstone

4 main groups based on 3 factors: 1) depth of emplacement below surface 2) range of temperature 3) type of rare element enrichment 4 groups: 1) Abyssal (high temperature, variable pressure) 2) Muscovite (low temperature, high pressure) 3) Rare-element (low temp, low press) --> produces most gemstones 4) Miarolite (medium temp, low press)

DIAMOND: physical properties

4Cs of Diamonds: Colour, Cut, Clarity, Carat Hardness: 10 on Mohs scale (at the top!) Durability: high Refractive index: high; 2.4 Dispersion: great (shows rainbow) Colour: pure diamond = colourless (but can occur with diff colours) 4 Properties used to Confirm Diamonds: thermal + electrical conductivities, refractive index, dispersion

Common Treatments of Gem Corundum

99% sapphires + rubies treated to change colours, intensify, increase clarity 1) heat treatment (colours, intensify, clarity) 2) diffusion treatment --> imparts variety of colours (colourless to Padparadscha sapphires)

Plate Tectonics

BASIC CONCEPT - geological Grand Unifying Theory -> explains geological phenomena in the world CONVERGENT PLATE BOUNDARIES - plates move together and collide - continental-continental convergent -> mountains - oceanic-oceanic -> chain of volcanoes - oceanic-continental -> oceanic plate subducts b/c it's denser -> mountain ranges DIVERGENT - plates move away at boundaries which produces new crust - can ultimately form new ocean basin TRANSFORM - plates move past each other - San Andreas Fault

Mineral Formula of Gem Beryl

Be3Al2Si6O18 - substitutions in octahedral Al site --> important; gives rise to vivid colours

Star Rubies

Burmese DeLong Star Ruby - 100.32 carats - American Museum of Natural History - stolen + returned with ransom Rosser Reeves Ruby - 138. 7 carats - Smithsonian

Local Distribution of Gold in BC + Canadian Shield

CANADIAN SHIELD - abundant gold mining comes from here - generally found in bands volcanic rocks -> "greenstone belts" - created from hydrothermal fluids that dissolved metals and then mobilized + concentrated into mineralization - Archean Hydrothermal Vein-Type deposits

Chain of Custody Principle vs. Kimberly Process Certification Scheme

CHAIN OF CUSTODY - employed by manufacturer in jewelry making - means each component + step leading to finished piece of jewelry is tracked + documented - ensures assessment + accountability of practices engaged - concept of tracking ---> MINE TO MARKET KPCS - applies only to gemstones, not jewelry like CoC

Extracting Information from Mineral Formula

CHEMICAL FORMULAS - Component Elements + Number of Atoms of each element - Diamond only has C; Quartz (SiO2) has 1 silicon atom and 2 oxygen atoms per formula unit - Round brackets to indicate solid solution - E.G. gem peridot (Mg, Fe)2SiO4 --> Mg and Fe all sum to 2; either Mg or Fe could occupy up to 2 atoms per formula unit

PYRALSPite Garnet Group

COLOUR RANGE - wide range from ruby red to emerald green FORMS OF GARNET CRYSTALS - Pyrope, Almandine, Sepssartine - Requires Al in structure

UGRANDite Garnet Group

COLOUR RANGE - wide range from ruby red to emerald green FORMS OF GARNET CRYSTALS - Uvarovite, Grossular, Andradite - Contains essential Ca in structure

Differences btwn Tourmaline Minerals + Gem Varieties

COLOURS --> similar to beryl, colour in tourmaline caused by transition elements subbing in structure for Al; gem varieties used to be distinguished through colour before chemical analyses -most tourmaline mineral species are elbaite Dravite - red - Fe+3 Indicolite - blue - Fe+2 and Ti+4 Rubellite - deep pink to red - Mn+2 and Mn+3 Verdelite - green - Fe+2 and Fe+3 "chrome" - green - Cr+3 or V+3 Canary - yellow - Mn+2 and Ti+4 Paraiba - electric blue - Cu+2 --> RAREST variety Watermelon tourmaline - pink n green - Mn and Fe

Tanzanite: Composition + Properties

COMPOSITION - Ca2Al3Si3O12(OH) --> V replacing Al and Ca - main gem variety of mineral zoisite - range of colours due to vanadium (V) - chromium can also lead to green colouration PROPERTIES - most prized colour = deep blue-purple colour + strongly trichoic - vibrant blue colour - orthrorhombic (three RI between 1.69 - 1.70) - Hardness: 6.5 - SG: 3.5 - Cleavage: perfect prismatic cleavage

Graphite vs Diamond

COMPOSITION - both composed of entirely carbon CRYSTAL STRUCTURE - significantly different - POLYMORPHISM --> same composition but diff. crystal structure - = different physical properties as a result BONDING - graphite --> carbon atoms partially covalently bonded in 2 dimensional sheets and are very weak - diamond --> carbon atoms strongly bonded in 3 dimensions

General Composition of Ancient Coinage + Source of Metals

COMPOSITION - gold + silver alloys - sometimes copper and copper alloys - has different artistic periods SOURCE - each part of globe had own special mineral resources - Europe, Northern Africa, Arabia --> facilitated growth of ancient civilizations there - Some of oldest precious metal thought to be originated from modern Bulgaria + Mediterranean - Greece --> Laurion - Cornwall + Brittany --> important source of copper + tin - Central European localities of Erzebirge and Harz --> exploited by Roman underground

Type Ia, Ib, IIa, IIb Diamonds

COMPOSITION Type I --> have N concentrations greater than 10 ppm Type Ia --> contains appreciable amounts of N CLUSTERED in crystal structure; most common Type Ib --> contains appreciable amounts of N; N is DISPERSED and SCATTERED; very rare Type II --> have N concentrations less than 10 ppm (i.e. nitrogen free) Type IIa --> no appreciable N or B; second most common Type IIb --> contains minute traces of B but no N; very rare (e.g. Hope Diamond) COLOUR Type Ia --> show overall yellow hue; absorbs blue light Type Ib --> yellow, brown, orange, green, colourless Type IIa --> lack of impurities = whitest colour with little absorption of light; physical deformations/defects give rise to pink, purple, brown diamonds Type IIb --> incorporation of Boron causes most light but blue to be absorbed; blue to grey hue

Demands for "responsible/ethical" products

CONSUMER DEMANDS: _ Origins of jewelry + impact on people there - Resulting largely from "Blood Diamond" movie - Sourcing "green" or "certified" products - Corporate, social, environmental responsibilities of mining INDUSTRY RESPONSE: - Kimberley Process -> industry-driven set of regulations to fight against trade of illicit diamonds - Initiative for Responsible Mining Assurance / Responsible Jewelry Council - Certification in Canada -> Maple Leaf Diamonds, CanadaMark, "Certified Canadian Gold"

Continental vs Oceanic Crust

CONTINENTAL - Richer in Silicon (Si) - Thicker OCEANIC - Higher in Iron (Fe) - Thinner CRUSTAL THICKNESS - thickness varies in time + space depending on geological processes happening - continental crust rarely thicker than 50km

Pearl, Amber, Coral

FORMATION - Amber --> fossilized tree resin from conifers + some flowering trees - Pearl --> natural concretions formed inside mollusks in response to an aggravating foreign particle; occurs naturally - Coral --> organic, coral reefs in oceans; controversial as it has had negative effects on coral reefs HOW IT'S DIFFERENT - originate from organic material - has similar qualities + characteristics as mineral-based gemstones

Global Distribution of Important Gem-Bearing Pegmatite Districts

Famous/Notable localities --> Brazil, Madagascar, Russia, Pakistan, US, Italy, Mozambique, Namibia, Afghanistan, MINAS GERAIS (most notable)

Layers + basic characteristics of Earth's Interior

From outer to inner LITHOSPHERE - continental + oceanic crust, uppermost part of mantle ASTHENOSPHERE - upper mantle - crustal lithospheric plates move on this soft lubricating layer MANTLE - hot viscous "taffy-like" layer - convection currents -> hot mantle rises from depth, upper mantle sinks; drives motion of lithospheric plates OUTER CORE - Liquid INNER CORE - Solid - Metallic composition

Periodic Table: General Structure + General Trends

GENERAL STRUCTURE - ordered by atomic number or elemental identity - arranged in rows (periods) - shape of table influenced by which electronic shells/orbitals available for filling each element - roughly organized w/ increasing weight (since it's ordered by atomic number) - 7 periods & 18 groups - Actinides + Lanthanides - Alkali Metals + Alkaline Earth Metals - Transition Metals - Semi-Metals - Metalloids - Non-metals - Halogen elements - Noble gases GENERAL TRENDS - will list GIVEN NAME (iron) - ATOMIC NUMBER = # of protons (26) - avg ATOMIC MASS (55.847 amu)

Geological Model: Primary Metamorphic Corundum in Gneisses and Marbles

GENETIC SETTINGS - provides significant volume of gem corundum from primary sources - produces most significant quality of rubies + sapphires GEOLOGICAL SETTINGS: - metamorphic rock (gneisses and marbles) can host gem corundum mineralizations - these rocks become enriched in Al and depleted in Si - famous examples of marble-hosted corundum localities --> Mogok - famous examples of gneiss-hosted corundum --> Sri Lanka

Global Distribution of Diamond Deposits

GEOGRAPHICALLY - Africa - Historically in India - Minas Gerais in Brazil ("new world") - S. Africa (Kimberley) - Russia --> Mir Diamond Mine - Australia --> Australian Arygle Mine - Canada --> Diavik, Ekati GEOLOGICALLY - diamond-bearing kimberlites occur in areas with archean-aged cratonic basement rocks - historically in India, Brazil, S. Africa - other areas of import: canadian shield, australia, russia

Distribution of Diamond Deposits in Canada

GEOGRAPHICALLY - Ekati Mine in NWT (1991) - Diavik Mine in NWT (2003) - Snap Lake Mine in NWT (2008) - Victor Mine in ON - Attawapiskat (2008) GEOLOGICALLY - diamond-bearing kimberlite

Important copper districts of world

GLOBAL INDUSTRY - 3rd most produced metal (after aluminum and steel) - mostly generated through mining (and then through recycling) - global fluctuations --> lower overall mine production; international labour laws; increasing mine operation costs; equipment/material shortages LARGEST IMPORTERS - Asia -> Japan and Korea TOP COPPER PRODUCERS - Chile, China, Peru, US SIGNIFICANT PRODUCERS - Australia, Russia, Zambia, Indonesia

The prominent uses for gold, PGMs and diamonds

GOLD - Jewelry production mostly - Electronics, currencies, investments PGM - High-tech applications - Primarily in autocatalysts - Jewelry - and then electronics DIAMONDS - Jewelry - Industrial applications -> most commonly as abrasives

Top producing countries for gold, Platinum Group Metals, and diamonds

GOLD - South Africa -> largest producer - China - Australia, North + South America - Canada is 8th largest producer PGM - South Africa -> one of 2 main producers; Bushveld Complex - Russia -> other main producer - US + Canada - Anglo Platinum Group Ltd. DIAMONDS - DeBeers Consolidated Mines -> Kimberley Mine in S. Africa - Australia's Argyle Mine - Canada's Ekati + Diavik

Two Core Techniques in Jewelry Making

HAND MAKING - historical method of creating jewelry and results in "one of a kind pieces" - basic steps --> 1) design 2) fabrication + stone setting 3) gold finishing and assembly INVESTMENT (LOST WAX) CASTING - innovative concept - requires multiple steps before finished products - 1) model created from material that can be carved 2) wax covered in multiple layers of refractory material 3) break the clay shell once metal is cooled and hardened 4) new metal form ready for polishing and gemstones - still used today, just more technologically advanced

Silver Ores: Common Geological Settings

HISTORICALLY - Ancient --> Greece + other parts of Eastern Europe - Recent historical --> Mexico + Peru - Canada

Synthetic Productions of Beryl

HYDROTHERMAL SOLUTIONS - most common procedure in growing sizeable beryl crystals -aquamarine not usually synthetically produced due to its abundance

Three Main Rock Types

IGNEOUS - rocks that crystallize/solidifies from magma - volcanic/extrusive: melt/magma cools to form at earth's surface - plutonic/intrusive: melt/magma cools to form inside Earth METAMORPHIC - alteration of pre-existing rocks via metamorphism - heat, pressure, percolating fluids, compression, new minerals --> metamorphizes rocks SEDIMENTARY 1) physical erosion --> clastic sedimentary rock 2) chemical precipitation --> evaporite 3) biological precipitation of mineral --> coral, shells, coal - sediments transformed into rock via lithification/diagenesis

DIFFERENCES: Ionic, Covalent, Metallic Bonding

IONIC BONDING - occurs between 2 atoms - when a cation "donates" electrons to the anion (cation becomes positively charged with less electrons; anion becomes negatively charged with more electrons) - EG. NaCl - most common bonding type in MINERAL WORLD COVALENT - 2 atoms "share" valence (outermost) electrons between them - more common in organic compounds - E.G. -> DIAMOND with CARBON (C) sharing electrons; gives diamond its strength METALLIC - less common in nature - valence electrons shared throughout entire material + free to move about (compared to covalent, which only allows for 2 atoms) E.G. SILVER, GOLD, COPPER

Isotropic vs. Anisotropic Minerals

ISOTROPIC MINERALS - minerals that belong to ISOMETRIC CRYSTAL SYSTEM - has only 1 refractive index applicable in all 3-dimension orientations - examples: diamond (n=2.419) ANISOTROPIC MINERALS - minerals from all crystal systems other than isometric - show more than 1 refractive index useful in identifying gemstones

Common Geological Settings of Lode Gold in Canada

MESOTHERMAL/OROGENIC - gold deposits formed at depths of 5-10 km - form through metamorphic rocks + tectonic activity - most common lode gold resource in Canada (85%) INTRUSION-RELATED - formed at depths 2-7 km - fluids transport gold that come from igneous intrusions such as granite - mostly occurs in Can Shield - next most common lode gold resource in Canada EPITHERMAL - forms at less than 1.5 km - normally consists of QUARTZ VEINS w/ precious metals or DISSEMINATED LOW-GRADE PRECIOUS METALS from HYDROTHERMAL FLUIDS - hydrothermal fluids involved in process - most preserved epithermal deposits in Canada are relatively young (Mesozoic or younger) - least common type in Canada

Rarity of Gem Corundum

MINERAL CORUNDUM - not that rare RARE GEM CORUNDUM - intensely coloured rubies, pink sapphires, blue sapphires -- > rare esp. if untreated - durability + historical significance of gem corundum - Cornflower blues; Pigeon's Blood Red; hot pinks --> difficult colours to generate naturally

RELATIONSHIP: Corundum, Ruby + Sapphire

MINERAL CORUNDUM -mineral corundum gives rise to RUBY and SAPPHIRE - basic mineral GEM CORUNDUM - most important of all coloured gemstones - fancy sapphires = gem corundum of any colour other than blue or red RUBY AND SAPPHIRE - comprise 2/3 of "Big Three" coloured gemstones (emerald is third)

MINERAL FORMULA + CRYSTAL STRUCTURE: Topaz

MINERAL FORMULA Al2SiO4(F, OH)2 - limited chemical variation but sometimes Cr noted in some pink samples CRYSTAL STRUCTURE - orthrorhombic crystal system - Si in structure tetrahedrally coordinated (has 4 oxygen anions) + Al is octahedrally coordinated (6 anions) - Unusual --> anions of Al octahedron is a mix of 4 O and 2 F

MINERAL FORMULA + CRYSTAL STRUCTURE: Spodumene

MINERAL FORMULA LiAlSi2O6 - significant substitution in Li and Al sites - Kunzite: Mn+3 for Al --> pink - Hiddenite: Cr+3 for Al --> green

Imitations of Gem Corundum

MISTAKEN IDENTIFICATIONS - many spinels + garnets thought to be ruby - kyanite, blue glass, topaz thought to be sapphire DOUBLETS - today, most imitations are where natural colourless ruby or sapphire has coloured synthetic corundum crystal glued underneath

Uses of Gold

MODERN - jewelry and currency - dental industry and electronics industry - medical field (circuitry of implants, delivery of drugs, treatments) - catalytic industry --> similar to PGMs HISTORY - art, religion, currency

Uses of Silver

MODERN 1) industrial applications (circuits, contacts, conductors, fuses, medical applications, socks, toothbrushes, etc) 2) jewelry ("the queen of metals", sterling silver) 3) photography (film, has to do with light and exposure; silver halide crystals) HISTORICAL - precious metal in coinage, jewelry, functional art - prized for its thermal conductivity, sensitivity, reflectance of light, mallebility, and ductility

Important Geological Settings of PGE Deposits

Main 5 PGE Geological Settings: 1) Sudbury Complex, Canada 2) Bushveld Complex, South Africa 3) Stillwater Complex, USA 4) Great Dyke, Zimbabwe 5) Noril'sk Region, Russia

Four Main Quartz Gem Varieties

OPAL - most precious AMETHYST - purple, violet, red-purple - associated with royalty and piety - en cabochon CITRINE - yellow to brownish - resembles topaz - occurs in localities with amethyst AGATE - common semiprecious type of chalcedony - many quartz artifacts throughout history