mineral
Prehnite with Epidote and Quartz
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Mohs hardness of 6 to 6.5, pale green to yellow color, vitreous to pearly luster, often forms botryoidal (globular or grape-like) aggregates, specific gravity of 2.80 to 2.95, distinct cleavage on {001}.
Identified More mineral →
Explore Prehnite with Epidote and Quartz in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6 to 6.5, pale green to yellow color, vitreous to pearly luster, often forms botryoidal (globular or grape-like) aggregates, specific gravity of 2.80 to 2.95, distinct cleavage on {001}.
Formation & geological history
Forms in low-grade metamorphic environments, typically in veins and cavities of mafic igneous rocks such as basalts, through hydrothermal alteration.
Uses & applications
Popular as a collector specimen, cut into cabochons, and used in distinctive artisan jewelry.
Geological facts
Prehnite was the first mineral to be named after a person, military commander Colonel Hendrik von Prehn, who discovered it in South Africa in the 18th century.
Field identification & locations
Easily recognized in the field by its characteristic pale green, botryoidal 'grape jelly' texture lining cavities within dark host basalt or diabase rocks.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral