Weloganite: Francon Quarry, Quebec Canada (0.37). Photo © Joel E. Arem, PhD, FGA. Used with permission.
An overview on Weloganite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Weloganite gems.
| Data | Value |
|---|---|
| Name | Weloganite |
| Colors | White, lemon yellow, amber. Crystals may be zoned. |
| Crystallography | Hexagonal; crystals hexagonal, barrel shaped with heavy striations on prism faces, also grooved due to oscillatory growth. Crystals distinctive, terminated by pedion or pyramids. Also massive. |
| Refractive Index | 1.558-1.648 |
| Luster | Vitreous. |
| Hardness | 3.5 |
| Fracture | Conchoidal |
| Specific Gravity | 3.20 |
| Birefringence | 0.090 |
| Cleavage | Perfect |
| Stone Sizes | Clean, yellowish stones (mostly under ½ carat) have been faceted from this material. National Museums of Canada (Ottawa, Ontario): 4.27 (light greyish-yellow); 0.52 (light yellow). |
| Luminescence | None reported. |
| Luminescence Present | No |
| Transparency | Translucent. |
| Absorption Spectrum | Not diagnostic. |
| Formula |
Sr5Zr2C9H8O31 |
| Pleochroism |
None. |
| Optics |
a = 1.558; β = 1.646; γ = 1.648. Uniaxial (-). |
| Optic Sign | Uniaxial - |
Optics: a= 1.558; β= 1.646; γ=1.648.
Uniaxial (-)
Occurrence: In an alkalic sill intruding a limestone at St. Michel, Montreal Island, Quebec, Canada.
Name: For William E. Logan, first director of the Geological Survey of Canada.
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