Museum Thomsonite is a very rare zeolite at Mont Saint-Hilaire. Color is usually colorless or white. Luster is vitreous to dull. Diaphaneity is transparent to translucent. Crystal Habits include fibrous crystals to 2mm and spherical aggregates to 8mm.
Fracture is uneven to subconchoidal.
Streak is white. Associated Minerals include aegirine, albite, analcime, apophyllite series, calcite, catapleiite, donnayite, fluorite, natrolite, pectolite, pyrophanite and s randite.