Cristobalite, Fayalite
Small Cabinet, 5.9 x 3.8 x 3.8 cm
Canyon Butte occurrence (Couger Butte), Canyon Butte, Siskiyou Co., California, USA
Obsidian(volcanic glass) cools too quickly, to crystallize. Thus, it is unusual to see minerals attached. The spheres of high temperature cristobalite(SiO2) are actually the result of devitrification, or loss of silica from the obsidian. Most unusual. 5.9 x 3.8 x 3.8 cm