Coal
Coal is a rock. It has a Mohs hardness of 1-3 (Mohs scale) and dull to slightly shiny luster.
Coal properties
| Type | Rock |
|---|---|
| Mohs hardness | 1-3 (Mohs scale) |
| Luster | Dull to slightly shiny |
| Typical colors | Black, brown, and sometimes with a glossy surface |
| Formation | Formed from the accumulation and compaction of plant material over millions of years |
| Rarity | 3 / 10 |
Mohs hardness 1–3 — soft
1 · Talc5 · Apatite10 · Diamond
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