| Poudretteite | |
|---|---|
 | |
| General | |
| Category | Cyclosilicate |
| Formula | KNa2B3Si12O30 |
| IMA symbol | Pou [1] |
| Strunz classification | 9.CM.05 |
| Dana classification | 63.02.01a.08 |
| Crystal system | Hexagonal |
| Crystal class | Dihexagonal dipyramidal (6/mmm) H-M symbol: (6/m 2/m 2/m) |
| Space group | P6/mcc |
| Unit cell | 1,221.72 ų |
| Identification | |
| Color | Colorless, Light pink |
| Crystal habit | Roughly equant barrel-shaped prismatic crystals |
| Cleavage | None |
| Fracture | Conchoidal, splintery |
| Tenacity | Brittle |
| Mohs scale hardness | 5 |
| Luster | Vitreous (Glassy) |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 2.51 |
| Density | 2.51 |
| Optical properties | Uniaxial (+) |
| Refractive index | 1.511 to 1.532 |
| Birefringence | 0.021 |
| Pleochroism | Colorless to pink |
| References | [2] [3] [4] [5] [6] |
Poudretteite is an extremely rare mineral and gemstone that was first discovered as minute crystals in Mont St. Hilaire, Quebec, Canada, during the 1960s. [6] The mineral was named for the Poudrette family because they operated a quarry in the Mont St. Hilaire area where poudretteite was originally found, and the quarry is currently owned by the United Kingdom based Salmon Mining Industries Inc. Poudretteite has a barely detectable radioactivity. [7]
