LiAl₄(AlSi₃)O₁₀(OH)₈

This sample of Cookeite is displayed in the Smithsonian Museum of Natural History. Cookeite is a mineral which contains lithium with the composition LiAl₄(AlSi₃)O₁₀(OH)₈. The sample at left is about 15 cm across and is from Minas Gerais, Brazil.