EOSC 210 Rock and Mineral Quiz
Magnetite (iron ore)
Colour: black Lustre: metallic - dull Streak: grey/black Hardness: >5.5 Specific Gravity: high Cleavage: none MAGNETIC!
Amphibole (Hornblende variety)
Colour: black Lustre: non-metallic - vitreous Streak: grey Hardness: >5.5 Specific Gravity: average Cleavage: two at 120 and 60 degrees
Biotite Mica (black mica)
Colour: black Lustre: non-metallic - glassy Streak: grey Hardness: <2.5 Specific Gravity: low Cleavage: single, perfect - produces sheets
Pyroxene (Augite variety)
Colour: black/brown/green Lustre: non-metallic - vitreous Streak: white/brown Hardness: >5.5 Specific Gravity: average Cleavage: two directions at 90 degrees
Pyrite (fool's gold)
Colour: black/gold Lustre: metallic - bright Streak: black Hardness: >5.5 Specific Gravity: high Cleavage: none Fracture: conchoidal
Quartz
Colour: clear/white, can be different colours Lustre: non-metallic - glassy Streak: none Hardness: >5.5 Specific Gravity: low Cleavage: none (only crystal faces) Fracture: can be conchoidal
Garnet (crystal)
Colour: deep red Lustre: non-metallic -resinous Streak: none Hardness: >5.5 Specific Gravity: average Cleavage: none
Olivine
Colour: green/grey Lustre: non-metallic - vitreous Streak: white/green Hardness: >5.5 Specific Gravity: average Cleavage: poor in 2 directions - 90 degrees
Chalcopyrite (copper ore)
Colour: green/grey/gold Lustre: metallic - dull Streak: none (dark green?) Hardness: 2.5 < x < 5.5 Specific Gravity: average Cleavage: poor
Galena (lead ore)
Colour: grey/silver Lustre: metallic - bright Streak: grey Hardness: 2.5 < x < 5.5 Specific Gravity: high Cleavage: perfect in 3 directions
Orthoclase (Potassium Feldspar)
Colour: light pink/orange Lustre: non-metallic - vitreous Streak: white Hardness: >5.5 Specific Gravity: average Cleavage: one perfect, one good, 90 degrees
Hematite (iron ore)
Colour: red/brown, white specks Lustre: metallic - dull Streak: reddish brown Hardness: >5.5 Specific Gravity: high Cleavage: none
Plagioclase (Na-rich Feldspar)
Colour: white/grey Lustre: non-metallic - vitreous Streak: white Hardness: >5.5 Specific Gravity: average Cleavage: one perfect, one good, 90 degrees
Calcite
Colour: white/translucent Lustre: non-metallic - glassy Streak: white Hardness: 2.5 < x < 5.5 Specific Gravity: low Cleavage: perfect in 3 directions (75/55 degrees) REACTS WITH HCl
Muscovite (white/clear mica)
Colour: white/transparent Lustre: non-metallic - glassy Streak: white Hardness: <2.5 Specific Gravity: low Cleavage: single, perfect - produces sheets
Schist
Grain size: medium-coarse Texture: Schistosity (alignment of micas) Protolith: mudstone -visible crystals, mica rich
Gneiss
Grain size: medium-coarse Texture: gneissosity (light + dark bands) Protolith: almost anything -distinctive banding, Augen
Slate
Grain size: very fine Texture: slatey Protolith: mudstone -breaks easily into sheets
Marble
Mineral composition: calcite Texture: fine to coarse crystals (massive) -doesn't scratch glass, reacts strongly to HCl
Quartzite
Mineral composition: quartz Texture: fine to coarse crystals (massive) Protolith: quartz-rich siltstone -scratches glass, no reaction to HCl
Chert
black + red stripes
Microcrystalline Limestone
black, tiny crystals, no visible layers, some small white spots
Shale (mudstone)
black, visible layers
Phaneritic
coarse grained crystals, cooled slowly deep within the Earth, (plutonic/intrusive rocks)
Glassy
extrusive rocks, cooled very quickly at Earth's surface
Felsic
feldspar + silica, less dense, lighter in colour (quartz, orthoclase, plagioclase, muscovite)
Granite
felsic, crystalline - phaneritic
Aphanitic
fine grained crystals, cooled rapidly with restricted crystal growth (volcanic/extrusive rocks)
Lithic Sandstone (greywacke)
grey, visible grains
Porphyritic Andesite
intermediate, crystalline, porphyritic
Pumice
intermediate, noncrystalline - aphanitic
Ash Tuff
intermediate, noncrystalline - fragmental
Evaporite
large crystals, red + white
Red Sandstone
light coloured, pinkish-red stripes
Conglomerate
little pebbles in reddish white cement
Basalt
mafic, crystalline - aphanitic
Gabbro
mafic, crystalline - phaneritic
Obsidian
mafic, noncrystalline - glassy
Mafic
magnesium + iron, more dense, darker in colour (biotite, amphibole, pyroxene, olivine)
Porphyritic
mix of fine grained and coarse grained crystals, part of material grew slowly, part grew quickly, (volcanic/extrusive rocks)
Minerals
naturally occurring, inorganic, crystalline solids with specific chemical structures
Fragmental
pyroclastic rocks, fragments of broken rock matter
Pyroxene vs. Amphibole?
pyroxene = dull cleavages at 90 degrees amphibole = reflective cleavages at 60 or 120 degrees
Arkosic Sandstone
visible grains, reddish colour
Gypsum
Colour: white/grey Lustre: non-metallic - vitreous/pearly Streak: white Hardness: <2.5 Specific Gravity: low Cleavage: good in one direction, fair in two others (60/120 degrees)
Crystal Habits
Cubic - pyrite and galena Prismatic: quartz Dodecahedron: garnet
Kyanite
-blue colouring -found in schist and gneiss
Staurolite
-dark red/brown -has twinning -found in schist and gneiss