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Name: |
prehnite |
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Class: |
Silicates |
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Chemistry: |
Ca2Al2Si3O10(OH)2 hydrous calcium aluminum silicate |
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Color(s): |
white, light green, gray, coorless, Streak: white |
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Hardness: |
6 - 6.5 |
SpecGrav: |
2.9 - 2.95 |
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Fracture: |
uneven |
Cleavage: |
perfect 1 direction |
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Crystal: |
orthorhombic (often forms in lamellar aggregates) rarely good crystals |
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Envronment: |
forms in cavities in basaltic rocks, low temperature hydrothermal fissures, and in limestone |
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Association: |
datolite, calcite, pectolite, quartz, zeolites |
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Locals: |
| New Zealand | India | Switzerland | Scotland | California, Colorado, Michigan/USA | |
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Misc: |
Named for the Dutch minerologist Hendrik von Prehn. It is sometimes faceted when crystals are found. |
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Photos |
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