Prehnite
JewelryWiki Editorial·3 sources·Reviewed 2026-08-04
Translucent yellow-green, usually cut as cabochons. The first mineral named after a person — Colonel Hendrik von Prehn.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 6–6½ [1] | — |
| Refractive index | 1.611–1.669 [1] | — |
| Specific gravity | 2.82–2.94 [1] | — |
| Chemical formula | Ca2Al2Si3O10(OH)2 [3] | — |
| Crystal system | Orthorhombic [2] | — |
Sources
- International Gem Society — reference charts (Mohs hardness, specific gravity, refractive index) — International Gem Society (IGS reference charts)
- Wikipedia — mineral article infoboxes (crystal system) — Wikipedia contributors (Wikipedia mineral infoboxes)
- Handbook of Mineralogy — Mineral Data Publishing / Mineralogical Society of America (Handbook of Mineralogy, Mineral Data Publishing)