RocksdayManganite vs Pyrolusite
The quickest way to tell Manganite from Pyrolusite: Manganite leaves a brown streak; Pyrolusite leaves black.
Black manganese oxide-hydroxide in striated prisms. The streak is brown, not black.
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
- Streak (rub on unglazed porcelain): Manganite leaves a brown streak; Pyrolusite leaves black.
- Luster: Pyrolusite looks metallic; Manganite doesn't.
Key differences
- Pyrolusite is softer, soils the fingers and has a black streak.
Side by side
| Property | Manganite | Pyrolusite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 4 | 2–6.5 |
| Luster | Submetallic | Metallic to earthy |
| Streak | Brown | Black |
| Colors | Black, Gray | Black, Gray |
| Crystal system | Monoclinic | Tetragonal |
| Specific gravity | 4.3–4.4 | 4.4–5.1 |
| Formula | MnO(OH) | MnO₂ |
| Found in | Ilfeld, Harz, Germany; Cornwall, England | Germany; Brazil |
Properties that are the same for both are grayed out.
How to identify manganite
- Black prisms with lengthwise striations.
- Reddish-brown to dark brown streak.
- Hardness 4 — a knife scratches it.
Crystal system: Monoclinic
Full Manganite 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
Frequently asked questions
What is the difference between manganite and pyrolusite?
Manganite is a mineral with a Mohs hardness of 4 and a submetallic luster, usually black or gray. Pyrolusite is a mineral (MnO₂) with a Mohs hardness of 2–6.5 and a metallic to earthy luster, usually black or gray.
How can you tell manganite from pyrolusite?
Manganite leaves a brown streak; Pyrolusite leaves black. Pyrolusite looks metallic; Manganite doesn't. Pyrolusite is softer, soils the fingers and has a black streak.
Could you tell them apart from a blurry close-up?
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