mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
AI-generated identification · may be incorrectHardness: 6-6.5 Mohs scale; Color: Pale green to yellow-green, or colorless; Luster: Vitreous to pearly; Crystal Structure: Orthorhombic; Specific Gravity: 2.8-2.95
- Hardness
- 6-6
- Color
- Pale green to yellow-green, or colorless
- Luster
- Vitreous to pearly
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Physical properties
Hardness: 6-6.5 Mohs scale; Color: Pale green to yellow-green, or colorless; Luster: Vitreous to pearly; Crystal Structure: Orthorhombic; Specific Gravity: 2.8-2.95
Formation & geological history
A secondary mineral formed in hydrothermal environments, typically found in cavities, veins, and fractures of basaltic volcanic rocks, often associated with zeolites.
Uses & applications
Primarily used as a gemstone for jewelry (cabochons and beads) and as a collector's mineral specimen.
Geological facts
Prehnite was the first mineral to be named after a person (Colonel Hendrik Von Prehn, 1788). It is often called 'Green Grape' or 'Cape Chrysolite' when found in South Africa.
Field identification & locations
Identifiable by its distinct bottle-green color and 'bubbly' or botryoidal habit in raw form. Often found in basalt quarries or volcanic deposits in locations like South Africa, Australia, and the USA.
