Chabazite
Bombay, India

This specimen measures 6cm x 10cm

Chabazite CaAl₂Si₄O₁₂^.6H₂O

Tectosilicates; hydrous calcium, sodium, aluminum silicate, usually with some sodium and potassium; zeolite group

Color and Luster: White, yellow, pink, red; vitreous; streak white

Hardness: 4-5

Cleavage: Poor in three directions, parallel to rhombohedral faces

Fracture: Uneven, brittle

Crystals: Hexagonal; usually rhombohedrons that resemble cubes because the angles between faces are near 90; also compact, usually showing penetrations twins

Photo by Mary Sutherland

Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals