IMA mineral species
Cornwallite
Cu₅(AsO₄)₂(OH)₄
Arsenate mineral.
Properties
⛏ Mohs hardness4.5
💅🪙🍶🔪💎
A steel knife scratches it, it won't scratch glass.
| Chemical formula | Cu₅(AsO₄)₂(OH)₄ |
|---|---|
| Elements | Cu, As, O, H |
| Crystal system | Monoclinic |
| Mohs hardness | 4.5 |
| Density | — |
| Streak | — |
| Color | — |
| IMA symbol | Cnw |
| Nickel–Strunz class | 8.BD.05 |
“—” means no reliable value in Wikidata yet. Check Mindat for full data.
Care & Handling
- 🪶 Soft, Scratches Easily Mohs 4.5: 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): Wheal Gorland, 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
- Cornwallite on Mindat.org
- Wikipedia article
- Wikidata item Q3693802 (source of this page's data – you can correct it there)
IMA mineral species
4–5
Monoclinic
GreenBlack
Soft, Scratches Easily