RocksdayCinnabar vs Proustite
How to tell them apart
Mercury sulfide and the main ore of mercury: bright scarlet, soft and very heavy. Toxic — handle with care.
Photo: H. Zell, CC BY-SA 3.0
A translucent scarlet silver sulfosalt that darkens when exposed to light.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Quick tests
- Heft: Cinnabar feels noticeably heavier for its size (specific gravity 8.1–8.2 vs 5.55–5.64).
Key differences
- Cinnabar is heavier and has no silver.
Side by side
| Property | Cinnabar | Proustite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2–2.5 | 2–2.5 |
| Luster | Adamantine to dull | Adamantine |
| Streak | Scarlet | Scarlet |
| Colors | Red | Red |
| Crystal system | Trigonal | Trigonal |
| Specific gravity | 8.1–8.2 | 5.55–5.64 |
| Formula | HgS | Ag₃AsS₃ |
| Found in | Almadén, Spain; Guizhou, China | Chañarcillo, Chile; Freiberg, Germany |
Properties that are the same for both are grayed out.
How to identify cinnabar
- Bright scarlet red with a scarlet streak.
- Very heavy.
- Soft — a fingernail or coin scratches it.
- Often coats white quartz or dolomite.
Crystal system: Trigonal
Full Cinnabar guide →How to identify proustite
- Translucent scarlet crystals with a brilliant luster.
- Darkens to gray in light.
- Scarlet streak.
Crystal system: Trigonal
Full Proustite guide →More comparisons
Could you tell them apart from a blurry close-up?
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