Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons
Inderite is very soft and difficult to cut, and only a few stones have been cut by hobbyists. There is plenty of cuttable material in existence, and although the material comes from only a few localities, it is not considered a great rarity. The surface of cut stones may become white and cloudy after cutting; care must be taken in storage and to dry the stones after cutting.
| Data | Value |
|---|---|
| Name | Inderite |
| Varieties | Kurnakovite |
| Alternate Common Names | Also known as Lesserite; dimorph of Kurnakovite. |
| Colors | Colorless; massive varieties white to pink. |
| Hardness | 2.5. |
| Fracture | Uneven |
| Cleavage | Perfect 1 direction |
| Stone Sizes | Gems over 50 carats or more could be cut from large transparent crystals. |
| Formula | Mg2B6O11 · 15H2O. |
| Crystallography | Monoclinic. Crystals prismatic, up to 10 x 1cm; nodular; acicular crystals also. |
| Refractive Index | 1.486-1.507 |
| Birefringence | 0.017-0.020. |
| Luminescence | None. |
| Luminescence Present | No |
| Absorption Spectrum | Not diagnostic. |
| Optics | a = 1.486-1.489; β = 1.488-1.493; γ = 1.504-1.507. Biaxial (+), 2V= 37-52°. |
| Optic Sign | Biaxial + |
| Luster | Vitreous; pearly on cleavage. |
| Specific Gravity | 1.78-1.86 |
| Transparency | Transparent. |
Optics: a = 1.486-1.489; β = 1.488-1.493; γ = 1.504-1.507.
Biaxial (+), 2V= 37-52°.
Occurrence: Borate deposits in arid regions.
Kern County, California: large crystals, often transparent. Inder borate deposit, Kazakhstan, USSR: as nodules in red clay.
Comments: Inderite is very soft and difficult to cut, and only a few stones have been cut by hobbyists. There is plenty of cuttable material in existence, and although the material comes from only a few localities, it is not considered a great rarity. The surface of cut stones may become white and cloudy after cutting; care must be taken in storage and to dry the stones after cutting.
Name: After the locality, Inder Lake, Kazakhstan, USSR.
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