Prehnite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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Prehnite Gemstones by Size
This table shows distribution of Prehnite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:1.11 cts
Heaviest:12.96 cts
Average:4.81 cts
Total photos:13
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| General Information | ||||||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Prehnite | ||||||||||||||||||||||
| Mohs Hardness | 6 to 6.5, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Specific Gravity | 2.80 to 2.95, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Tenacity | Brittle, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Cleavage Quality | Distinct, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Fracture | Uneven, Gemstones (2009) | |||||||||||||||||||||
| Optical Properties of Prehnite | ||||||||||||||||||||||
| Refractive Index | 1.611 to 1.673, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Optical Character | Biaxial/+, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Birefringence | 0.020 to 0.036, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Pleochroism | Nil, Gemstones (2009) | |||||||||||||||||||||
| Dispersion | Nil, Gemstones (2009) | |||||||||||||||||||||
| Chatoyancy | Yes, Gemmological Tables (2004) | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Greenish, green, yellowish-green, brownish-green, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Transparency | Transparent,Translucent, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Lustre | Vitreous,Pearly, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Crystallography of Prehnite | ||||||||||||||||||||||
| Crystal System | Orthorhombic, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Habit | Radiating fibrous aggregate, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||
| Where found: | Occurs as a secondary or hydrothermal mineral in veins or cavities in mafic volcanic rocks or in granite gneisses or syenites, Gems, Sixth Edition (2006) | |||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Prehnite information at mindat.org | |||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||
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