Name:

prehnite

A photo of the mineral prehnite

Class:

Silicates

Chemistry:

Ca2Al2Si3O10(OH)2 hydrous calcium aluminum silicate

Color(s):

white, light green, gray, coorless, Streak: white

Hardness:

6 - 6.5

SpecGrav:

2.9 - 2.95

Fracture:

uneven

Cleavage:

perfect 1 direction

Crystal:

orthorhombic (often forms in lamellar aggregates) rarely good crystals

Envronment:

forms in cavities in basaltic rocks, low temperature hydrothermal fissures, and in limestone

Association:

datolite, calcite, pectolite, quartz, zeolites

Locals:

| New Zealand | India | Switzerland | Scotland | California, Colorado, Michigan/USA |

Misc:

Named for the Dutch minerologist Hendrik von Prehn. It is sometimes faceted when crystals are found.

Photos
& Locals:

1.) Paterson, New Jersey

2.) Paterson, New Jersey

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