H628Apophyllite and Stilbite with Scolecite fan. Apophyllite is a mineral occurring typically as white glass prisms, usually as a secondary mineral in volcanic rocks. It is a hydrated silicate and fluoride of calcium and potassium. Stilbite is the name of a series of tectosilicate minerals of the zeolite group. Both are interconnected to create an extraordinary piece. Lucite stand included. Size: 8" wide x 6" high x 2" deep