Pyrite
Mineral FeS2
Also called Fool's gold and Iron pyrites
Take care.
- Breaks down in damp air: Keep it dry and in steady humidity; some crumble or rot as they take on moisture.
About it
Pale brass-yellow cubes, pyritohedrons, and octahedrons, far harder than gold and brittle, with a greenish black streak. Famous cubes from Navajún, Spain, and Huanzala, Peru; some specimens decay in damp air.
- Type
- Mineral
- Group
- Sulfide, pyrite group
- Formula
- FeS2
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 4.95–5.1
- Streak
- greenish black to brownish black
- Lustre
- metallic
- Crystal system
- Isometric (cubic)
- Colours
- pale brass yellow, tarnishing darker or iridescent
- Transparency
- opaque
- Cleavage and fracture
- indistinct cubic; conchoidal to uneven fracture, brittle
Typical values: real specimens vary. For more, see mindat.org.