NaCa₁₆AlSi₂₄O₆₀ (OH)₈ .14H₂O

This sample of gyrolite is displayed in the Smithsonian Museum of Natural History. Gyrolite is a silicate mineral with the composition NaCa₁₆AlSi₂₄O₆₀(OH)₈.14H₂O. The sample at left is about 6 x 8 cm across and is from Bombay, Maharashtra, India. It is described as gyrolite with mesolite and calcite.