IMA mineral species
Birnessite
(Na,Ca,K)₀.₆(Mn⁴⁺,Mn³⁺)₂O₄·(H₂O)₁.₅
Hydroxide mineral.
Properties
⛏ Mohs hardness1.5
💅🪙🍶🔪💎
Scratches with a fingernail.
⚖ Density1.5 g/cm³
Light
| Chemical formula | (Na,Ca,K)₀.₆(Mn⁴⁺,Mn³⁺)₂O₄·(H₂O)₁.₅ |
|---|---|
| Elements | Na, Ca, K, Mn, O, H |
| Crystal system | — |
| Mohs hardness | 1.5 |
| Density | 1.5 g/cm³ |
| Streak | — |
| Color | — |
| IMA symbol | Bir |
| Nickel–Strunz class | 4.FL.45 |
“—” means no reliable value in Wikidata yet. Check Mindat for full data.
Care & Handling
- 🪶 Soft, Scratches Easily Mohs 1.5: softer than a steel knife, so it scratches easily. Store it apart from harder stones.
🌍 Where it's found
Type locality (where it was first described): Birness (Ellon), United Kingdom
Learn more
- Birnessite on Mindat.org
- Wikipedia article
- Wikidata item Q3640357 (source of this page's data – you can correct it there)
IMA mineral species
1–2
BrownBlack
Soft, Scratches Easily