Mineral Identification Quiz: Native Elements & Sulfides

Copper

• Chemical formula: Cu

• Hardness: 2.5-3 (between fingernail and penny)

• Specific Gravity: 8.9 (heavy)

• Cleavage: N/A

• Fracture: uneven

• Luster: metallic

• Streak: brownish/bronze

• Color: brown (oxidized)/green (acid)

• Other: opaque

Graphite

• Chemical formula: C

• Hardness: 1-2 (fingernail)

• Specific Gravity: 2 (light)

• Cleavage: perfect

• Fracture: flaky

• Luster: metallic

• Streak: grey/silver

• Color: silver-grey

• Other: opaque

Sulfur

• Chemical formula: S

• Hardness: 1.5-2.5 (between fingernail and penny)

• Specific Gravity: 1-2 (light)

• Cleavage: poor in 2 directions

• Fracture: brittle

• Luster: resinous

• Streak: white

• Color: yellow

• Other: opaque

Arsenopyrite

• Chemical formula: FeA_sS

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster: metallic

• Streak:

• Color:

• Other:

Bornite

• Chemical formula: Cu₅FeS₄

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Chalcopyrite

• Chemical formula: CuFeS₂

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Galena

• Chemical formula: PbS

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Pyrite

• Chemical formula: FeS₂

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Pyrrhotite

• Chemical formula: Fe_1-xS

• Hardness: 3.5-4

• Specific Gravity: 4.5-4.7 (heavy)

• Cleavage: N/A

• Fracture: subconchoidal

• Luster: non-metallic, dull

• Streak: black

• Color: brown/black with gold flecks

• Other: opaque

Spahlerite

• Chemical formula: ZnS

• Hardness: 3.5-4 (between penny and glass plate)

• Specific Gravity: 3.9-4.1 (heavy)

• Cleavage: perfect

• Fracture: conchoidal

• Luster: metallic

• Streak: white (strong smell)

• Color: blackish gold, brownish yellow

• Other: opaque

Realgar

• Chemical formula: AsS

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Orpiment

• Chemical formula: As₂S₃

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak: orange

• Color: reddish-orange/yellow

• Other:

Covellite

• Chemical formula: CuS

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Stibnite

• Chemical formula: Sb₂S₃

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:

Cinnabar

• Chemical formula: HgS

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other:
  

Marcasite

• Chemical formula: FeS₂

• Hardness:

• Specific Gravity:

• Cleavage: N/A

• Fracture: Yes

• Luster:

• Streak:

• Color:

• Other:

Enargite

• Chemical formula: Cu₃AsS₄

• Hardness:

• Specific Gravity:

• Cleavage:

• Fracture:

• Luster:

• Streak:

• Color:

• Other: