Poudretteite (Type Locality)
KNa₂B₃Si₁₂O₃₀

     Poudretteite, a member of the milarite group, was first described from MSH. It occurs rarely at Mont Saint-Hilaire.

PHYSICAL CHARACTERISTICS:

Color is usually colorless to very pale pink.
Luster is vitreous.
Diaphaneity is transparent.
Crystal System is hexagonal; P6/mcc.
Crystal Habits include rough hexagonal crystals, and etched barrel-
   shaped prisms to 5mm.
Cleavage is not observed.
Fracture is splintery to conchoidal.
Hardness is 5.
Specific Gravity is approximately 2.5 g/cm³.
Streak is white.
Associated Minerals include aegirine, apophyllite series and pectolite.
Distinguishing Features: Crystal habit and etching of crystals.
Origin: Named in 1987 after the Poudrette family, operators of the quarry
   in which the mineral was found.

CLASSIFICATION:

REFERENCES:
CanMin 25:763-766 (1987) ,MinRec 21:330 (1990), Dana 8:1275 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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