Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons
Zunyite
An overview on Zunyite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Zunyite gemstone.
Zunyite Information
| Data | Value |
|---|---|
| Name | Zunyite |
| Colors | Colorless, grayish, pale beige—brown. |
| Crystallography | Isometric, typically in tetrahedral crystals, rarely octahedrons; twinned. |
| Refractive Index | 1.600 |
| Luster | Vitreous. |
| Hardness | 7 |
| Specific Gravity | 2.87 |
| Birefringence | None. |
| Cleavage | Easy 1 direction |
| Stone Sizes | Cuttable zunyite may be found in Japanese material but has never been reported. However, in 1986 enormous (up to 2 cm) crystals of zunyite were found in a prospect pit near Quartzsite, Arizona. These are perfect tetrahedra, pale beige—brown in color, in matrix. Minute areas of some of these crystals were perfectly transparent, colorless, and suitable for cutting into faceted gems up to ½ carat in size. |
| Luminescence | Fluoresces intense red (Quartzsite). |
| Luminescence Present | Yes |
| Luminescence Type | Fluorescent |
| Transparency | Transparent to translucent. |
| Absorption Spectrum | Not diagnostic. |
| Formula |
Al13Si5O20(OH,F)18Cl. |
| Pleochroism |
None. |
| Optics |
N = 1.600. |
Optics: N =1.600.
Occurrence: At the type locality, the Zuni mine, near Silverton, Colorado, enclosed in guitermanite; also as a vein mineral in Ouray County, Colorado, and as an alteration product of feldspar in a dike rock in Saguache County.
Quartzsite, Arizona: large crystals.
Postmasburg, South Africa: in aluminous shales.
Kuni village, Gamma Prefecture, Japan: transparent tetrahedral crystals.
Algeria.
Name: After the type locality in Colorado.
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