| General Information |
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| A variety or type of: | Agate, which is a variety of Chalcedony, which is a variety of Quartz |
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| Chemical Formula | Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Physical Properties of Sardonyx |
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| Mohs Hardness | 6.5 to 7Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Specific Gravity | 2.55 to 2.70Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Optical Properties of Sardonyx |
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| Refractive Index | 1.530 to 1.543Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Optical Character | Uniaxial/+Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Birefringence | 0.008 to 0.010Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Colour |
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| Colour (General) | Straight white band of onyx with brownish red band of sardHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Transparency | Translucent,OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Lustre | Waxygemdat.org, Management Team (2012) |
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| Crystallography of Sardonyx |
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| Crystal System | TrigonalUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Habit | Fibrous to grained aggregateUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Further Information |
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| Mineral information: | Sardonyx information at mindat.org |
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