QU
Silicate / 01Quartz
SiO₂- Hardness
- 7–7
- Streak
- White
- Lustre
- Vitreous
DIAGNOSTIC CLUE No cleavage; shell-shaped fracture
Trusted properties.
Practical identification.
Consult a structured reference of key mineral properties, diagnostic indicators and field-observation criteria.
CA
Carbonate / 02Calcite
CaCO₃- Hardness
- 3–3
- Streak
- White
- Lustre
- Vitreous, Pearly
DIAGNOSTIC CLUE Strong reaction with dilute acid
MA
Oxide / 03Magnetite
Fe₃O₄- Hardness
- 5.5–6.5
- Streak
- Black
- Lustre
- Metallic
DIAGNOSTIC CLUE Strongly magnetic with black streak
PY
Sulfide / 04Pyrite
FeS₂- Hardness
- 6–6.5
- Streak
- Greenish-black
- Lustre
- Metallic
DIAGNOSTIC CLUE Brassy cubes; brittle, not malleable
FL
Halide / 05Fluorite
CaF₂- Hardness
- 4–4
- Streak
- White
- Lustre
- Vitreous
DIAGNOSTIC CLUE Perfect cleavage in four directions
GY
Sulfate / 06Gypsum
CaSO₄·2H₂O- Hardness
- 2–2
- Streak
- White
- Lustre
- Pearly, Silky
DIAGNOSTIC CLUE Scratched easily by a fingernail
HE
Oxide / 07Hematite
Fe₂O₃- Hardness
- 5–6
- Streak
- Reddish-brown
- Lustre
- Metallic, Earthy
DIAGNOSTIC CLUE Diagnostic reddish-brown streak