descriptive mineral table Flashcards
(27 cards)
1
Q
graphite
A
- C
- elemental carbon
- silver grey
- black streak
- marks paper, feels greasy, one chief direction of cleavage
2
Q
galena
A
- PbS
- lead sulfide
- silver-grey
- black streak
- bright, metallic luster, dense, cubic cleavage
3
Q
pyrite
A
- FeS2
- iron disulfide
- light brass-yellow
- black streak
- poor cleavage, fragile, fool’s gold
4
Q
magnetite
A
- Fe3O4
- iron oxide
- black
- black streak
- magnetic, granular, or octahedral crystal, no cleavage, dense
5
Q
talc
A
- Mg3Si4O10(OH)2
- hydrous magnesium silicate
- white to pale green
- pearly luster
- extremely soft, feels soapy, one chief direction of cleavage
6
Q
native sulfur
A
- S
- yellow
- resinous
- sulfur odor, low density and hardness
7
Q
gypsum
A
- CaSO4 x 2H20
- hydrous calcium sulfate
- colorless, white, pale orange
- vitreous/pearly
- selenite is clear/satin spar is fibrous, cleavage in one direction best developed
8
Q
kaolinite
A
- Al2Si2O5(OH)4
- hydrous aluminosilicate
- white, cream
- earthy, dull
- soft, powdery texture, smells earthy when damp
9
Q
biotite mica
A
- K(Mg,Fe)3AlSi3O10(OH)2
- hydrous potassium aluminum ferromagnesian silicate
- dark brown, black
- vitreous
- peels into thin, elastic, greenish-brown sheets along one direction of cleavage
10
Q
muscovite mica
A
- KAl2(AlSi3O10)(OH)2
- hydrous potassium aluminum silicate
- colorless, pale green
- vitreous to pearly
- transparent mica, peels into thin, elastic, transparent sheets along one direction of cleavage
11
Q
halite
A
- NaCl
- sodium chloride
- colorless, salmon, pastels
- vitreous to greasy
- cubic cleavage, tastes salty
12
Q
calcite
A
- CaCO3
- calcium carbonate
- colorless, white, rarely pastels
- vitreous
- effervesces freely in cold dilute HCl, rhombohedral cleavage
13
Q
earthy hematite
A
- Fe2O3
- iron oxide
- dull brownish red to bright red
- submetallic to earthy
- commonly earthy and too powdery for hardness test, no cleavage, red-brown streak
14
Q
hornblende
A
- complex hydrous ferromagnesian silicate with Ca, Al, Na
- greenish black to black
- vitreous
- shiny on cleavage faces, slintery at edges, 124 and 56 degree cleavage angles
15
Q
augite
A
- similar to hornblende, but anhydrous
- dark green to black
- vitreous
- duller and greener than hornblende, 87 and 93 degree cleavage, uneven fracture
16
Q
orthoclase feldspar (k feldspar)
A
- KAlSi3O8
- potassium aluminosilicate
- white, pink, salmon
- vitreous
- wavy internal pattern, two good cleavages at 90 degrees, will scratch glass
17
Q
plagioclase feldspar
A
- NaAlSi3O8, CaAl2Si2O8
- sodium and/or calcium aluminosilicate
- white, grey
- vitreous
- two good cleavages at 90 degrees, will scratch glass
18
Q
olivine
A
- (Mg,Fe)2SiO4
- olive green
- vitreous
- conchoidal fracture, color distinctive
19
Q
quartz
A
- SiO2
- colorless, white, grey, various
- vitreous
- 6 sided, conchoidal fractures, no cleavage
20
Q
garnet
A
- Fe3Al2(SiO4)3
- iron-calcium-magnesium aluminum silicate
- brown, red
- vitreous/resinous
- dodecahedral crystals, no cleavage
21
Q
chlorite
A
- hydrous aluminous ferromagnesian silicate
- light to dark green
- vitreous to earthy
- flakes are not elastic, mica-like
22
Q
native gold
A
-Au
-gold, rose, white
-same as color
gold streak, dense
23
Q
dolomite
A
- CaMg(CO3)2
- calcium magnesium carbonate
- white, yellow, pink
- vitreous to pearly
- in cold HCL, effervesces slowly when powdered
24
Q
fluorite
A
- CaF2
- calcium fluoride
- colorless, purple
- vitreous
- cubic or octahedral crystals, octahedral cleavage
25
staurolite
- FeAl4Si2O10(OH)2
- hydrous iron aluminosilicate
- brown
- vitreous to dull
- twinned to form diagnostic cruciform crosses
26
topaz
- Al2SiO4(OH,F)2
- hydrous fluoroaluminosilicate
- colorless,white,golden
- vitreous
- one direction of basal cleavage,striations on crystal faces
27
diamond
- C
- elemental carbon
- colorless, pastels
- adamantine to greasy
- hardest natural substance, four well developed directions of cleavage
