Thomsonite

Thomsonite is a zeolite mineral that forms in cavities of basaltic volcanic rocks. It typically occurs as radiating clusters, compact spherical aggregates, or prismatic crystals lining vesicles. Colors are commonly white, cream or pale grey, with occasional pink, green or yellow/orange tones. Crystals have a vitreous to silky luster and are often associated with other zeolites such as stilbite, natrolite and mesolite.