Lab 1: Minerals Flashcards
Amphibole
cleavage in 2 directions - 60° and 120°**
vitreous lustre
dark green to black**
long, prismatic eight-sided crystal
amphibole hardness
6
Biotite
1 plane of cleave cleavage **
black to brownish black**
vitreous luster
biotite hardness
2.5-3
Calcite
strongly effervesces in HCL**
double image seen through clear pieces**
3 cleavage planes not at 90°**
vitreous luster
calcite hardness
3
Chalcopyrite
massive
golden yellow/greenish yellow**
metallic luster**
Hardness 3-4**
chalcopyrite hardness
3.5-4
Dolomite
reacts slowly with HCl**
cleavages in 3 directions - 75°**
dolomite hardness
3.5-4
Galena
3 excellent cubic cleavage**
high specific density**
silver-grey
metallic luster
galena hardness
2.5
Gypsum
hardness of 2**
excellent cleavage in 1 direction, poor cleavage in other two directions**
vitreous to pearly** luster
white or transparent
Halite
salty taste**
perfect cleave at 90°**
halite hardness
2-2.5
Magnetite
magnetic**
dark grey to black
irregular fracture
Muscovite
1 plane of cleavage**
colourless**
flexible in thin sheets**
muscovite hardness
2-3
Olivine
olive green colour**
occurs as aggregates of small vitreous grains**
transparent to translucent
Plagioclase Feldspar
striations**
2 good cleavages at 90°**
white to dark grey
plagioclase feldspar hardness
6
olivine hardness
6.5-7.5
Potassium Feldspar
exsolution texture**
pink salmon colour**
potassium feldspar hardness
6
Pyrite
metallic luster**
massive/cubic habit**
brass-yellow**
pyrite hardness
6-6.6
Pyroxene
dull luster (don’t write this)
2 directions of cleavage at 90°**
dark green to black
short prismatic eight sided crystals
pyroxene hardness
6
Quartz
conchoidal fracture**
six sided crystal habit
hardness of 7
Sphalerite
resinous luster**
yellow streak*
dodecahedral cleavage (12 planes)
sphalerite hardness
3.5-4
Sylvite
bitter taste**
3 directions of cleavage at 90°**
Finger nail hardness
2.5
penny hardness
3.5
glass plate hardness
5.5
steel nail
6.5
Streak plate hardness
7
talc hardness
1
gypsum hardness
2
calcite hardness
3
fluorite hardness
4
apatite hardness
5
feldspar hardness
6
quartz hardness
7
topaz hardness
8
corundum hardness
9
diamond hardness
10
acicular habit
needle like; silimanite
bladed habit
elongated in one dimension, substantially smaller in the the other two; kyanite
prismatic habit
like quartz habit
equant habit
a cube; pyrite
tabular habit
feldspar; one dimension shorter than other two
platy habit
biotite; one dimension substantially smaller than the other two
granular
rounded-irregular shaped crystals; sugar like in appearance
what should be used to differentiate between chalcopyrite and pyrite
hardness;
chalcopyrite = 3.5 - 4
pyrite = 6-6.6
basal cleavage
1 direction of cleavage;
biotite, muscovite
prismatic cleavage
2 cleavages at 90°;
feldspars, pyroxene
non-prismatic cleavage
2 cleavages not at 90°;
amphibole
cubic cleavage
3 cleavages at 90°;
halite, galena
rhombohedral cleavage
3 cleavages, none at 90°;
calcite
octahedral
4 cleavages - 8 faces;
fluorite
dodecahedral
6 cleavages - 12 faces;
sphalerite
sulphide minerals
(squares)
sphalerite
galena
chalcopyrite
pyrite
carbonate minerals
(reacts with acid)
dolomite
calcite
aragonite
sulphate minerals
(absorbs water)
gypsum
anhydrite
oxide minerals
(interesting)
magnetite, haematite
alumina/corundum
uraninite
halide minerals
(salty)
fluorite
halite
sylvite
single tetrahedra silicate minerals
olivine
single chain silica minerals
pyroxene
double chain silica minerals
amphibole
sheet silica minerals
muscovite, biotite
3d framework silica minerals
potassium feldspar
quarts