Wollastonite
CaSiO₃

     Wollastonite is uncommon at MSH. Originally known as wollastonite-1T, it is now referred to as wollastonite-1A. No other polytypes are known at Mont Saint-Hilaire.

PHYSICAL CHARACTERISTICS:

Color is usually white to pale gray.
Luster is vitreous.
Diaphaneity is transparent to translucent.
Crystal System is triclinic; P1.
Crystal Habits include fine-grained to fibrous aggregates and small
   phenocrysts to 2mm.
Cleavage {100} is perfect; {001} and {102} are good.
Fracture is splintery.
Hardness is 4.5 - 5.
Specific Gravity is approximately 2.9 g/cm³.
Streak is white.
Associated Minerals include calcite.
Distinguishing Features: Crystal habit.
Origin: Named in 1818 for William Hyde Wollaston (1766-1828),
   English mineralogist and chemist.

CLASSIFICATION:

REFERENCES:
MinRec 21:347 (1990), Dana 8:1315-1316 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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