It bears very close ressemblance to pectolite and is easily overlooked. Color is usually white to colorless. Luster is vitreous to silky to dull. Diaphaneity is translucent to opaque. Crystal Habits include aggregates of crude hexagonal prisms to 3mm on pectolite.
Fracture is conchoidal to uneven.
Hardness is 5.5 - 6. Streak is white. Associated Minerals include aegirine, apophyllite group, calcite, fluorite, pectolite and poudretteite. Crystal habit and its triated nature. Named in 1870 after its occurrence at Val Millar, Switzerland.