mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
AI-generated identification · may be incorrectHardness: 6-6.5 Mohs scale; Color: Pale green to yellow-green; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Cleavage: Good; Specific Gravity: 2.80-2.90.
- Hardness
- 6-6
- Color
- Pale green to yellow-green
- Luster
- Vitreous to pearly
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Physical properties
Hardness: 6-6.5 Mohs scale; Color: Pale green to yellow-green; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Cleavage: Good; Specific Gravity: 2.80-2.90.
Formation & geological history
Formed via low-grade metamorphism in cavities of mafic volcanic rocks (basalt). It is a secondary mineral resulting from hydrothermal alteration of plagioclase feldspars.
Uses & applications
Commonly used as a gemstone for jewelry (cabochons and beads) and highly valued as a mineral specimen for collectors.
Geological facts
Named after Colonel Hendrik Von Prehn in 1788, it was the first mineral to be named after a person. It is often found associated with minerals like zeolites and epidote.
Field identification & locations
Identified by its signature 'apple green' color and translucent, botryoidal (grape-like) habit in raw form. Commonly found in South Africa, Australia, and the USA.
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