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www.mineralgallery.co.za Minerals P-T |
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Prehnite |
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Name
Prehnite
Chemistry
Ca2Al2Si3O10(OH)2 Hydrous calcium Aluminum silicate
Uses
As a mineral specimen
Color
White, green, gray or even colorless
Hardness
6-6.5
Specific gravity
2.9 - 2.95
Crystals
Tabular usually globular.
Accompanied by:
Zeolites, barite, quartz, calcite.
Fracture
Uneven.
Luster
Vitreous.
Cleavage
Basal good.
Streak
White
Similar to:
Zeolites.
Prehnite is a very attractive mineral that can have a very good luster.
It forms in cavaties in basaltic rocks. It also forms in low temperature hydrothermal fissures in limestone. Associated minerals are
datolite
calcite
pectolite
zeolites
It was named after the Dutch minerologist Hendrik von Prehn. It can be facetted or carved into ornaments. Sometimes it is carved so well that it may resemble jade.
