Chapter 4 exploring geo
O (oxygen) and Si (silicon) make up
74% of earths crust with the rest being mostly aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), magnesium (Mg)
Silicate Minerals
Account for over 90% of the minerals in earths crust 2. include quartz, feldspar, mica, olivine, pyroxene 3. contain silicon-oxygen tetrahedra
What happens at the atomic scale when a mineral cleaves or fractures?
If all bonds have the same strength, they may not be arranged in such a way as to allow cleavage planes to form; mineral fractures 2. If different bonds between atoms have different strengths, the mineral will cleave along the weakest bond. 3. if all bonds have the same strength, they may be arranged in such a way that the mineral cleaves along three planes without passing through an atom
The mineral in the image is quartz. take a look at the irregularly broken face at the center of the crystal and determine which of the following is true?
The mineral has fractures, as it lacks cleavage planes
Elements colored purple and blue include
U (uranium), and many that are less familiar. Atomic number higher than 92 are not known in natural settings (produced in lab) except for Pu (plutonium) this produced by nuclear reactions
Independent tetrahedra
minerals (like olivine) do not break along clearly defined planes; all bonds are almost equally strong.
Chemical elements are (periodic table)
the fundamental building blocks of minerals, mineral groups based on the main chemical components within minerals.
Silicate minerals are the most important rock-forming minerals because
they comprise most of the earth's crust and mantle.
Elements colored yellow are called
transition metals, include Cr (chromium), Fe (iron), Ni (nickel), Cu (copper), Zn (zinc), Ag (silver), Au (gold).
There are more than 4,000 known minerals, most of which are
uncommon to rare ( knowing only a few dozen of the most common minerals will allow you to identify most rock types)
What are two main ways that geologic minerals are used in society?
As source of elements and compounds that we use to manufacture other products. 2. For some of their special properties, color, density, and resistance to heat or abrasion, etc.
Table begins with
H (hydrogen), the lightest element and advances to higher atomic numbers and heavier elements from left to right from top to bottom.
Lightest and simplest elements
H (hydrogen), He (helium) are most abundant elements in universe
What is true about asbestos?
Blue asbestos poses a severe health risk 2. Chrysotile white asbestos does not pose a significant health risk unless breathed in large amounts for a long time.
What may be said of the mica mineral in the image?
Bonds between atoms within sheets are stronger than those between atoms linking the sheets. 2. The mineral cleaved along one set of planes to split into thin sheets.
Elements in the green are nonmetals and include
C (carbon), Si (silicon), O (oxygen). Nonmetals bond with both types of metallic elements to form minerals.
Types of Cleavage
One direction cleavage (minerals in mica family) one set of parallel planes, forming thin sheets. 2. Three perpendicular directions of cleavage (cleaves along three perpendicular sets of planes broken faces have stair-step geometry and mineral commonly breaks into cubes (halite) 3. Two perpendicular directions of cleavage (minerals cleave along 2 sets of planes that are perpendicular to one another, right angle 90 degrees steps along broken crystal faces. pyroxene mineral group has right-angle cleavage. 4. Three non-perpendicular directions of cleavage (mineral cleaves along three directions of planes that are shaped like rhombi, or sheared box. Calcite. 5. Two non-perpendicular directions of cleavage (2 planes of cleavage can intersect at angles other than 90 percent. minerals with this cleavage can break into pieces having corners that do not form right angles. (amphibole group)
Term refers to compound SiO2
Silica (known as silicon dioxide)
Major classes of rock-forming minerals?
Silicates (quartz) are most important mineral group on earth. contains silicon and oxygen (2 abundant elements in crust). Silicates, each silicon atom is bonded only to oxygen. Linked by bonds to metals Fe, Mg, Na, K, Ca and Al. 2. Carbonates (carbon and oxygen bonded together in a triangular arrangement. linked by metal calcium (Ca), ex. calcite (CaCO). 3. Oxides consist of oxygen bonded with a metal (iron in mineral hematite (Fe2O3)) 4. Halides contain chorine (Cl) or fluorine (F), both are nonmetals that bond with metal from left side of table (halite (NaCI)) halide mineral. 5. Sulfates contain sulfur (S) only bonded to oxygen. Sulfur oxygen units are bonded to metal, calcium or iron. Gypsum common sulfate. 6. Sulfides contain sulfur bonded with metal, such as iron or copper. mineral pyrite called fools gold.
Elements shades orange
alkali and alkali earth metals, Na (sodium), K (potassium), Ca (calcium), Mg (magnesium), on the left side of table and Al (aluminum), and elements on right side of table.
rank the following in order from smallest to largest, with smallest on top
electron atomic nucleus single atom of an element mineral
double chains
half the tetrahedra share two O atoms and half share three; minerals cleave parallel to structure and along two planes at 60 degrees and 120 degrees.
Periodic table
has an atomic symbol, one or two letters represent the name of the element, atomic number upper left corner. Elements share background color based on similar chemical properties.
A silicon-oxygen tetrahedron ______
has one silicon atom bonded with four oxygen atoms, forms a building block for the vast majority of minerals on earth, may join with other tetrahedra or cations to form different types of silicates and a wide variety of minerals.
Nonsilicate minerals
include calcite, hematite, pyrite, gypsum and halite 2. do not contain silicon 3. include carbonates, oxides, sulfides, sulfates and halides
The most common minerals in the upper part of the continental crust are ________. They are fells in composition, and their color is direct result of their elemental composition.
light colored silicates
electrons
negatively charged particles in orbit around the nucleus of an atom
last column in periodic table includes elements called
noble gases because does not readily combine with other elements.
atomic mass
numbers of positively charged plus neutrally charged particles in an atom
What do silicate minerals contain?
one silicon atom is bonded with four oxygen atoms to form the negatively charged SiO4-4 complex. This has important shape called tetrahedron that controls many aspects of silicate minerals. forms building block for vast majority of minerals on earth.
nucleus
part of the atom that contains the protons and neutrons
neutrons
parts of the atom that do not have a charge
protons
parts of the atom with a positive electrical charge
frameworks
tetrahedra share four O atoms; quartz, with no cleavage or feldspar with cleavage.
sheets
tetrahedra share three oxygen atoms; cleavage of minerals(like micas and clays) is in one main direction.
single chains
tetrahedra share two O atoms and are strongly bonded; cleavage is parallel to the bonded tetrahedra
electron shell
the different energy states of negatively charged atomic particles arranged around the nucleus of an atom