Smokey Quartz
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| Data | Value |
|---|---|
| Name | Smoky Quartz |
| Is a Variety of | Quartz |
| Varieties | Morion |
| Crystallography | Hexagonal (trigonal) |
| Refractive Index | 1.544-1.553 |
| Colors | Every shade of brown. |
| Hardness | 7 |
| Wearability | Very Good |
| Fracture | Conchoidal to uneven |
| Birefringence | 0.009 |
| Cleavage | None or indistinct |
| Dispersion | 0.013 |
| Absorption Spectrum | Not diagnostic. |
| Pleochroism | Dark stones: weak brown/reddish brown. Light stones: weak, light and darker yellowish brown. |
| Optics | o = 1.544; e = 1.553 (very constant). Uniaxial (+). |
| Optic Sign | Uniaxial + |
| Luster | Vitreous. |
| Polish Luster | Vitreous. |
| Fracture Luster | Vitreous. |
| Specific Gravity | 2.651 |
| Enhancements | Heating (occasional). |
| Typical Treatments | Heat Treatment |
| Transparency | Transparent to opaque. |
Comments
Smoky quartz is also mistaken for topaz. It comes in every shade of brown, from a light tan to nearly black. “Chocolate citrine” is a pleasant brownish/yellow color. Smoky quartz is known for its large sizes. The person who wants a really big gem, without a really big budget, often ends up with one of these.
Sources
Stone Sizes
Smoky quartz: is in the same size league as citrine, but larger stones get very dark and opaque. Smithsonian Institution (Washington, D.C): 4500 (California) and 1695 (Brazil), plus others.
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