Color varies from silver white to gray. It tarnishes to pale bronze and steel gray. Luster is metallic. Diaphaneity is opaque. Crystal Habits include prismatic crystals, crude elongated plates and massive.
Fracture is uneven.
Hardness is 5 - 5.5. Streak is greyish-black. Associated Minerals include analcime, biotite, sodalite and vesuvianite.