mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
AI-generated identification · may be incorrectHardness: 6-6.5; Color: pale green to yellow; Luster: vitreous to pearly; Crystal structure: Orthorhombic; Specific gravity: 2.80-2.90
- Hardness
- 6-6
- Color
- pale green to yellow
- Luster
- vitreous to pearly
Identified More mineral →
Explore Prehnite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-6.5; Color: pale green to yellow; Luster: vitreous to pearly; Crystal structure: Orthorhombic; Specific gravity: 2.80-2.90
Formation & geological history
Commonly forms as a secondary mineral in vesicular cavities of mafic volcanic rocks like basalt; often associated with zeolites. Formatively typically hydrothermal or metamorphic in age.
Uses & applications
Used primarily as a gemstone for jewelry (cabochons or beads) and as a decorative mineral specimen for collectors.
Geological facts
It was the first mineral to be named after a person, Colonel Hendrik Von Prehn, who discovered it in South Africa in 1788.
Field identification & locations
Identified by its distinctive 'apple-green' color and botryoidal (grape-like) habit in the field. Found in South Africa, Australia, and the USA.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
sedimentary