Kurnakovite
Kurnakovite is a borate that is unusual and a really unusual treasure which is difficult to cut due to cleavage and softness. The chemical composition of this stone is MgB3O3(OH)5·5H2O and its crystal habit, Rough prismatic crystals, to 37 cm; typically in dense aggregates. It really is just like and a dimorph of Inderite. Both minerals are colorless and pretty uninteresting as gems except for their rarity. There are particular locations being few Kurnakovite is located and just one location where crystals big enough for faceting have now been found. Relatively crystals that are large been found at the Kramer Borate deposit, Boron, Kern County, California, USA.
| Category: | Nesoborates |
| Chemical Formula: | MgB3O3(OH)5·5H2O |
| Crystallography: | Triclinic – Pinacoidal |
| Crystal Habit: | Rough prismatic crystals, to 37 cm; typically in dense aggregates |
| Twinning: | Infrequent, on an unknown law |
| Cleavage: | [110] Good, [001] Indistinct |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Hardness (Mohs): | 2.5 – 3.0 |
| Density: | 1.847 – 1.862 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioacitve |
| Other: | Insoluble in water. Soluble in warm acids. |
| Color: | Colorless, White |
| Transparency: | Transparent, Translucent |
| Luster: | Vitrious, Pearly |
| Refractive Index: | 1.488 – 1.525 Biaxial ( – ) |
| Birefringence: | 0.027 – 0.034 (very high) |
| Dispersion: | Weak, r > v |
| Pleochroism: | None |
