Poudretteite
Appearance
Poudretteite | |
---|---|
General | |
Category | Cyclosilicate |
Formula (repeating unit) | KNa2B3Si12O30 |
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 |
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 |
Optical properties | Uniaxial + |
Refractive index | 1.511 to 1.532 |
Birefringence | 0.021 |
Pleochroism | Colorless to pink |
References | [1][2][3][4][5] |
Poudretteite is an extremely rare mineral and gemstone that was first discovered as minute crystals in Mont St. Hilaire, Quebec, Canada, during the 1960s.[5] The mineral was named for the Poudrette family because they operated a quarry in the Mont St. Hilaire area where poudretteite was originally found.[6]