Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
orthorhombicuncommonSilicates
Prehnite
Ca₂Al(AlSi₃O₁₀)(OH)₂
This specimen features pale green, botryoidal (grape-like) aggregates of Prehnite, forming rounded, translucent masses, with some associated white Laumontite crystals.
Prehnite Physical Properties
Mohs Hardness
6Crystal System
orthorhombicLuster
vitreousStreak Color
whiteCleavage
good on {001}Fracture
unevenSpecific Gravity
2.85Colors
pale green, yellowish-green, white, gray, colorlessTransparency
translucentType Locality
Malad, Ward 38, Mumbai (Bombay), Mumbai District (Bombay District), Maharashtra, IndiaMineral Group
SilicatesUses
jewelry, carving material, collectorAssociated Minerals
laumontite, zeolites, calcite, epidote, quartzRarity
uncommonGeological Context
Prehnite typically forms as a secondary mineral in the vesicles and veins of basaltic and other mafic igneous rocks, often associated with zeolites, due to low-grade metamorphic or hydrothermal alteration processes.
