mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
AI-generated identification · may be incorrectHardness: 6-6.5 on Mohs scale; Color: Pale green to yellow-green; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Specific Gravity: 2.80-2.95
- Hardness
- 6-6
- Color
- Pale green to yellow-green
- Luster
- Vitreous to pearly
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Physical properties
Hardness: 6-6.5 on Mohs scale; Color: Pale green to yellow-green; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Specific Gravity: 2.80-2.95
Formation & geological history
Typically forms as a secondary or hydrothermal mineral in cavities of mafic volcanic rocks like basalt. It often occurs as a result of low-grade metamorphism.
Uses & applications
Primarily used as a gemstone for jewelry (beads, cabochons) and as a collector's mineral specimen.
Geological facts
Prehnite was the first mineral to be named after a person, Colonel Hendrik Von Prehn, who discovered it in South Africa in 1788. It is often found associated with zeolites.
Field identification & locations
Identified by its distinct oil-green color and 'grape-like' (botryoidal) habit in its natural state. Commonly found in South Africa, Australia, and the United States (New Jersey).
