Chemistry:Poudretteite

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Poudretteite
Poudretteite-382457.jpg
General
CategoryCyclosilicate
Formula
(repeating unit)
KNa2B3Si12O30
Strunz classification9.CM.05
Dana classification63.02.01a.08
Crystal systemHexagonal
Crystal classDihexagonal dipyramidal (6/mmm)
H-M symbol: (6/m 2/m 2/m)
Space groupP6/mcc
Unit cell1,221.72 ų
Identification
ColorColorless, Light pink
Crystal habitRoughly equant barrel-shaped prismatic crystals
CleavageNone
FractureConchoidal, splintery
TenacityBrittle
Mohs scale hardness5
|re|er}}Vitreous (Glassy)
StreakWhite
DiaphaneityTransparent
Specific gravity2.51
Density2.51
Optical propertiesUniaxial (+)
Refractive index1.511 to 1.532
Birefringence0.021
PleochroismColorless 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, and the quarry is currently owned by the United Kingdom based Salmon Mining Industries Inc. Poudretteite has a barely detectable radioactivity.[7]

References