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: 2.80–2.90.
- 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: 2.80–2.90.
Formation & geological history
Formed in cavities of basaltic lavas, volcanic rocks, and occasionally in metamorphic rocks through hydrothermal processes. Often found as a secondary mineral.
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, who discovered it in South Africa in 1788.
Field identification & locations
Identify by its translucent 'bottlegreen' color and characteristic globular (botryoidal) growth habit. Commonly found in South Africa, Australia, and the USA (New Jersey).
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