| General Information |
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| A variety or type of: | Common Opal, which is a variety of Opal |
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| Chemical Formula | Walter Schumann, Gemstones of the world (2001) |
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| Physical Properties of Moss Opal |
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| Mohs Hardness | 5.5 to 6.5Walter Schumann, Gemstones of the world (2001) |
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| Specific Gravity | 1.98 to 2.50Walter Schumann, Gemstones of the world (2001) |
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| Tenacity | BrittleWalter Schumann, Gemstones of the world (2001) |
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| Cleavage Quality | NoneWalter Schumann, Gemstones of the world (2001) |
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| Fracture | Conchoidal,SplinteryWalter Schumann, Gemstones of the world (2001) |
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| Optical Properties of Moss Opal |
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| Refractive Index | 1.37 to 1.52Walter Schumann, Gemstones of the world (2001) |
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| Birefringence | NoneWalter Schumann, Gemstones of the world (2001) |
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| Pleochroism | AbsentWalter Schumann, Gemstones of the world (2001) |
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| Colour |
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| Colour (General) | MilkyWalter Schumann, Gemstones of the world (2001) |
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| Transparency | Translucent,OpaqueWalter Schumann, Gemstones of the world (2001) |
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| Crystallography of Moss Opal |
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| Crystal System | AmorphousWalter Schumann, Gemstones of the world (2001) |
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| Inclusions in Moss Opal |
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| Generally fine-grained chlorite, often mixed with clay minerals. - Opal, Lithographie, 2007, p. 59 |
| Further Information |
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| Mineral information: | Moss Opal information at mindat.org |
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| Significant Gem Localities |
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| USA | | |
| Laurs and Quinn (2003) |
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