RocksdayCalaverite vs Pyrite
How to tell them apart
A gold telluride — an ore of gold that looks nothing like gold.
Photo: Didier Descouens, CC BY-SA 4.0
Brassy iron sulfide famous as 'fool's gold'. It often forms startlingly perfect cubes with fine parallel lines on the faces.
Photo: Ivar Leidus, CC BY-SA 4.0
Quick tests
- Scratch glass: Pyrite scratches glass (Mohs 6–6.5); Calaverite can't (Mohs 2.5–3).
- Streak (rub on unglazed porcelain): Calaverite leaves a greenish yellow streak; Pyrite leaves greenish black.
- Heft: Calaverite feels noticeably heavier for its size (specific gravity 9.1–9.3 vs 4.95–5.1).
Key differences
- Pyrite is much harder and lighter.
Side by side
| Property | Calaverite | Pyrite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2.5–3 | 6–6.5 |
| Luster | Metallic | Metallic |
| Streak | Greenish yellow | Greenish black |
| Colors | Silver, Gold | Gold |
| Crystal system | Monoclinic | Cubic |
| Specific gravity | 9.1–9.3 | 4.95–5.1 |
| Formula | AuTe₂ | FeS₂ |
| Found in | Cripple Creek, Colorado; Kalgoorlie, Western Australia | Navajún, Spain; Huanzala, Peru |
Properties that are the same for both are grayed out.
How to identify calaverite
- Brassy-silver metallic blades.
- Very heavy.
- Heating drives off tellurium, leaving beads of gold.
Crystal system: Monoclinic
Full Calaverite guide →How to identify pyrite
- Pale brass-yellow metallic color.
- Streak is greenish black, not gold.
- Hard and brittle — it shatters rather than flattens when struck.
- Cubes with striated faces, or twelve-sided pyritohedrons.
Crystal system: Cubic
Full Pyrite guide →More comparisons
Could you tell them apart from a blurry close-up?
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