Inderite
Inderite, also referred to as Lesserite, is a relatively rare borate mineral but extremely rare as a gem that is faceted. It’s very soft and tough to cut due to its softness and cleavage that is ideal. Inderite is formed in Borate deposits in arid regions.
You can find very areas which can be few Inderite can be located but only one source for gem quality crystals which is Boron, Kramer District, Kern County, California, USA.
| Chemical Formula: | MgB3O3(OH)5 · 5(H2O) |
| Hydrated Magnesium Borate Hydroxide | |
| Molecular Weight: | 279.85 gm |
| Composition: | Magnesium | 8.69 % | Mg | 14.40 % | MgO |
| Boron | 11.59 % | B | 37.32 % | B2O3 | |
| Hydrogen | 5.40 % | H | 48.28 % | H2O | |
| Oxygen | 74.32 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | As long prismatic crystals with nearly square cross-section, to 30 cm; may be as aggregates of minute needles; reniform nodular, massive. |
| Twinning: | None |
| Cleavage: | Perfect on {010}, Good on {110} |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 2.5 – 3.0 |
| Density: | 1.80 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Insoluble in water. Readily soluble in warm, dilute HCl. |
| Color: | Colorless to White, Pink |
| Transparency: | Translucent to Transparent |
| Luster: | Vitreous to Pearly on cleavages, Dull, Greasy |
| Refractive Index: | 1.488 – 1.505 Biaxial ( + ) |
| Birefringence: | 0.0170 |
| Dispersion: | Weak; r > v |
| Pleochroism: | None |
