RocksdayGraphite vs Pyrolusite
How to tell them apart
Soft, black carbon in stacked sheets — the 'lead' in pencils.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Manganese dioxide, usually black and sooty; it leaves black marks on fingers.
Photo: Unknown authorUnknown author, Public domain
Quick tests
- Hardness: Pyrolusite is clearly harder: Mohs 2–6.5 versus 1–2.
- Heft: Pyrolusite feels noticeably heavier for its size (specific gravity 4.4–5.1 vs 2.09–2.23).
Key differences
- Graphite is slippery and lighter.
Side by side
| Property | Graphite | Pyrolusite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 1–2 | 2–6.5 |
| Luster | Metallic to dull | Metallic to earthy |
| Streak | Black | Black |
| Colors | Black, Gray | Black, Gray |
| Crystal system | Hexagonal | Tetragonal |
| Specific gravity | 2.09–2.23 | 4.4–5.1 |
| Formula | C | MnO₂ |
| Found in | Borrowdale, England; Sri Lanka | Germany; Brazil |
Properties that are the same for both are grayed out.
How to identify graphite
- Leaves black marks on paper and fingers.
- Greasy, slippery feel.
- Light for a metallic-looking mineral.
Crystal system: Hexagonal
Full Graphite guide →How to identify pyrolusite
- Sooty black masses that dirty your fingers.
- Black streak.
- Fern-like black 'dendrites' on rock surfaces.
Crystal system: Tetragonal
Full Pyrolusite guide →More comparisons
Could you tell them apart from a blurry close-up?
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