Inderite
| Inderite | |
|---|---|
| General | |
| Category | Minerals |
| Formula | MgB3O3(OH)5 · 5H2O |
| IMA symbol | Idr |
| Strunz classification | 6.CA.15 |
| Dana classification | 26.3.1.3 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) |
| Space group | P21/b |
| Unit cell | 1,041.64 ų |
| Identification | |
| Formula mass | 279.85 |
| Color | Colorless, white, pink; colorless in transmitted light |
| Cleavage | Perfect on {010}, on {110} good |
| Fracture | Uneven |
| Mohs scale hardness | 2.5 – 3 |
| Luster | Vitreous, greasy, pearly, dull |
| Diaphaneity | Transparent, translucent |
| Density | 1.8 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.488 nβ = 1.491 nγ = 1.505 |
| Birefringence | 0.017 |
| Pleochroism | None |
| 2V angle | Measured 37°, calculated 52° |
| Dispersion | Weak, r > v |
| Ultraviolet fluorescence | None |
| Solubility | Soluble in hydrochloric acid |
| Other characteristics | Pearly on cleavages |
Inderite, also known as lesserite, is a mineral that was named after its source, the Inder lake, near the Inder Mountains in Kazakhstan. The samples were described in English by the soviet mineralogist Boldyreva in 1937. It is a rare secondary mineral but common in salt, potassium and borate deposits.