Xonotlite
| Xonotlite | |
|---|---|
Combination piece with radial fibrous inesite and xonotlite | |
| General | |
| Category | Inosilicates |
| Formula | Ca6Si6O17(OH)2 |
| IMA symbol | Xon |
| Strunz classification | 9.DG.35 |
| Dana classification | 66.3.1.1 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P2/a |
| Unit cell | 879.33 |
| Identification | |
| Color | White, grey, pale pink, lemon white, colorless |
| Cleavage | Perfect, Good |
| Fracture | Splintery, tough |
| Mohs scale hardness | 6.5 |
| Luster | Vitreous, silky, pearly |
| Streak | White |
| Diaphaneity | Transparent, translucent |
| Specific gravity | 2.70 – 2.72 |
| Density | Measured: 2.70 – 2.72 Calculated: 2.71 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.583 nβ = 1.585 nγ = 1.595 |
| Birefringence | 0.012 |
| 2V angle | 50° |
| Ultraviolet fluorescence | Short UV = weak gray-white Long UV = weak white |
| Common impurities | Fe, Mn, H2O |
Xonotlite, or eakleite, is a mineral of general formula Ca6Si6O17(OH)2 named by the German mineralogist Karl Friedrich August Rammelsberg in 1866. The name originates from its discovery locality, Tetela de Xonotla, Puebla, Mexico. Although it was discovered in 1866, it was first described in 1959. It is approved by the IMA, but it is a grandfathered species, meaning the name supposedly represents a valid species til this day.