Judging quality
Natural Spanish cubes sit in a marl matrix with mirror-bright faces and fine striations. Beware brassy plated fakes and heavily oiled specimens. Pyrite suns from Illinois are flat radial discs, not cubes.
Sulfide
Pyrite
Iron sulfide that grows in astonishingly perfect cubes, dodecahedra and radiating suns. The Navajun mine in Spain produces cubes so sharp they look machined.
Care
Can oxidise in humid air, developing a white sulfate bloom. Keep dry, and never store in a sealed damp case.
History & lore
Its name is from Greek pyr, fire — pyrite struck against steel throws sparks, a use that predates matches by millennia.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Pyrite
- What is Pyrite?
- Iron sulfide that grows in astonishingly perfect cubes, dodecahedra and radiating suns. The Navajun mine in Spain produces cubes so sharp they look machined.
- How hard is Pyrite and what is it made of?
- Pyrite is a Sulfide-family mineral with the composition FeS2. It crystallizes in the isometric system and rates 6-6.5 on the Mohs hardness scale. It occurs in brass, gold.
- Where does Pyrite come from?
- Notable localities for Pyrite include Spain (Navajun), Peru, Italy (Elba), China.
- How do you tell good Pyrite from filler?
- Natural Spanish cubes sit in a marl matrix with mirror-bright faces and fine striations. Beware brassy plated fakes and heavily oiled specimens. Pyrite suns from Illinois are flat radial discs, not cubes.
- How do you care for Pyrite?
- Can oxidise in humid air, developing a white sulfate bloom. Keep dry, and never store in a sealed damp case.
See it in person
Photographs only go so far
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.