minerals
Pyrite ("Fool's Gold")
The brassy impostor — metallic gold color, iron-hard, and cubic crystals that fooled every gold rush.
Core Biological & Field Specifications
Hardness
6–6.5 (scratches glass)
Streak
Greenish-black to brownish-black
Luster
Metallic
Lookalike
Gold (gold is softer, malleable, yellow streak)