Mineralogy Flash Cards

minerals that will be on the final exam

Chalcopyrite

CuFeS𝟐

brass yellow, tarnishes to bronze

streak: greenish-black

crystal system: tetragonal

uneven fracture, brittle

Spharlerite

ZnS

brass yellow, tarnished to bronze/iridecent

streak: greenish-black

perfect cleavage

Halite

NaCl

whitish/colorless

cleavage: 3 planes @ 90 degrees (cubic)

CS: isometric

salty to taste

Pyrite

FeS𝟐

pale brass-yellow, darker when tarnished

streak: brownish-black

crystal system: isometric

uneven cleavage; harder than gold

Fluorite

CaF𝟐

purple/green/yellow

cleavage: 3 planes @ 90 degrees

streak: white

CS: isometric

transparent and dull when massive

Galena

PbS

color/streak: lead-gray

cleavage: pefect - subconchoidal (3@90)

CS: isometric

opaque with high specific gravity

Copper

Cu

copper, green when oxidized (statue of liberty)

high specific gravity

CS: isometric

cleavage: none/hackly

opaque and malleable

Apatite

[Ca𝟓(PO𝟒)𝟑(Cl/F/OH)]

green, yellow, blue to violet, pink, brown

CS: hexagonal

cleavage: conchoidal

prismatic crystals, transparent/translucent

Calcite

CaCO𝟑

white, yellow, orange, red, etc.

cleavage: 30 ≈ 90 degrees

CS: hexagonal (trigonal)

transparent/translucent, reacts with acid

Corundum

Al𝟐O𝟑

colorless, RED, pink, yellow, etc.

cleavage: uneven

CS: trigonal (hexagonal)

very hard, hexagonal shape (rubies)

Brucite

Mg(OH)𝟐

white, light greenish, grayish, bluish

CS: hexagonal

cleavage: perfect & fibrous

transparent/translucent, pearly cleavage

Rhodochrosite

MnCO𝟑

pink, rose, red, yellowish-gray, brown, white

cleavage: 3 planes @ 90 degrees

CS: trigonal (hexagonal)

commonly pink/red, rhombohedral cleavage

Augite

(Cax Mgy Fez)(Mgy Fez1)Si𝟐O𝟔

black

streak: greenish-white

CS: monoclinic

cleavage: 2 planes @ 87 & 93 degrees

imperfect prismatic cleavage

Diopside

CaMgSi𝟐O𝟔

white to light green

streak: white, gray, green

CS: monoclinic

cleavage: {110} @ 87 & 93 degrees; 2 planes

imperfect prismatic cleavage, low S.G.

Orthoclase

K(AlSi𝟑O𝟖)

white, greenish white/grayish yellow/ PALE PINK

steak: white

cleavage: perfect

CS: monoclinic

transparent/translucent; pearly cleavage

Gypsum

(CaSO𝟒 ⋅ 2H𝟐O)

colorless, white, grey (shades: yellow, red, brown, etc)

streak: white

CS: monoclinic

cleavage: 2/3 planes

can scratch w/ fingernail (soft); clear tabular crystals

Topaz

Al𝟐(SiO𝟒)(F,OH)𝟐

white, PALE BLUE, light green, yellow, red, yellowish-brown

streak: white

CS: orthorhombic

cleavage: perfect {001}

translucent

Stibnite

Sb𝟐S𝟑

lead-gray with pale blue tint

streak: lead gray

CS: orthorhombic

cleavage: perfect on 2 planes; sub-conchoidal fracture

opaque, streak same as color

Olivine

M𝟐SIO𝟒

olive green, yellow green

streak: white to colorless

CS: orthorhombic

cleavage: 2 planes @ 90 degrees

glassy luster, HCl reactivity

Sillimanite

Al𝟐(SiO𝟒)O

colorless, white, yellow, brown, green, blue, gray

streak: white

CS: orthorhombic

cleavage: perfect {001}

fibrous with breakage along fiber boundaries, BRITTLE

Barite

BaSO𝟒

white, yellow, red, light blue, COLORLESS

streak: white

CS: orthorhombic

cleavage: 2/3 planes

high S.G. due to barium content, not hard (2.5-3.5)

Kyanite

Al𝟐(SiO𝟒)O

BLUE, white, light gray, (rare: yellow, orange, pink)

streak: COLORLESS

CS: triclinic (hexagonal)

cleavage: perfect

splintery and translucent

Anorthite

Ca(Al𝟐Si𝟐O𝟖)

colorless, reddish grey, white

streak: white

CS: triclinic

cleavage: perfect on {001}, less so on {010}, imperfect on {110}

vitreous/pearly, transparent/translucent

Albite

Na(AlSi𝟑O𝟖)

white, colorless gray

streak: white

CS: triclinic (hexagonal)

cleavage: perfect on [001], good [010], imperfect {110}

twinning striations on [001], 

Sphalerite

ZnS

brass-yellow, tarnished to bronze/iridescent

streak: greenish-black

CS: isometric

cleavage: 1 plane - perfect

Sulfur

S

bright yellow (brownish, orange, reddish)

CS: orthorhombic

cleavage: uneven

resinous luster, smells when burned, low density and soft

Andalusite

Al𝟐SiO𝟓

white when pure, flesh red, reddish-brown, olive green w/ impurities

cleavage: 2 sets of cleavage planes intersecting @89 degrees

CS: orthorhombic

nearly square prisms, looks like a flower when cut in half, low specific gravity: 3