Minerology Quiz 1 Prep

Magnetic Minerals

Pyrrhotite, magnetite, hematite

Bornite

Purple sheen

Galena

Cubic, metallic, hefty, hardness ~3

Cinnabar

No streak, painted red, earthy

Chalcocite

Light gray/brown streak, earthy, 3-5

Pyrite

Metallic, golden, dark gray streak, sharp cubic form, hardness 5-7

Chalcopyrite

“Painted yellow” gold, dark “green” grey streak, ~5.5 hardness

Pyrrhotite

Magnetic dark gold+grey, dark grey streak, 5-7 hardness

Realgar

Bright red, soft

Orpiment

Bright yellow / orange, earthy

Sphalerite

Adamantine, black, white streak, hardness <7, prismatic, dodecahedral cleavage

Corundum

Vitreous, hardness ~9, prismatic

Magnetite

Magnetic, dark grey, earthy+adamantine

Ilmenite

Metallic, black, dull red/brown streak, (weakly magnetic?), 5-6 hardness

Rutile

Black (+red and pink) with a light yellow streak, adamantine prismatic

Goethite

Black, brown streak, hardness 5-5.5, brown-yellowish brown streak, silky earthy, limonite variety, can be botryoidal

Hematite

Brownish-red streak, slightly magnetic

Either goethite or ilmenite

Has a brown streak but isn’t magnetic, look at luster and crystal habit