IMA mineral species
Bannisterite
(Ca,K,Na)(Mn²⁺,Fe²⁺)₁₀(Si,Al)₁₆O₃₈(OH)₈ * nH₂O
Smectite, phyllosilicate mineral.
Properties
⛏ Mohs hardness4
💅🪙🍶🔪💎
A steel knife scratches it, it won't scratch glass.
| Chemical formula | (Ca,K,Na)(Mn²⁺,Fe²⁺)₁₀(Si,Al)₁₆O₃₈(OH)₈ * nH₂O |
|---|---|
| Elements | Ca, K, Na, Mn, Fe, Si, Al, O, H |
| Crystal system | — |
| Mohs hardness | 4 |
| Density | — |
| Streak | — |
| Color | — |
| IMA symbol | Ban |
| Nickel–Strunz class | 9.EG.75 |
“—” means no reliable value in Wikidata yet. Check Mindat for full data.
🌍 Where it's found
Type locality (where it was first described): Franklin, United States · Benallt Mine, United Kingdom
- Type locality
- Notable source / deposit
- Country of origin
Marker positions are approximate (region or locality level). Type localities from Wikidata; notable sources curated by Crystopedia.
Learn more
- Bannisterite on Mindat.org
- Wikipedia article
- Wikidata item Q424817 (source of this page's data – you can correct it there)
IMA mineral species
4–5
Brown