Okenite with Gyrolite
Bombay, India

This specimen measures 12cm x 18cm




Okenite      Ca10Si18O46.18H2O

Complex silicate containing both chain and sheet structures

Color and Luster: Colorless to white, also pale yellow or blue; pearly

Hardness: 4.5-5

Cleavage: One direction

Fracture: Flexible fibers

Crystals: Radial aggregates of filiform crystals

Gyrolite      NaCa16(Si23Al)O60(OH5).15H2O

Sheet silicate, secondary mineral in basalt(diabase) cavities

Color and Luster: White, cream to gray, rarely green or brown; vitreous to pearly

Hardness: 3-4

Cleavage: Perfect in one direction

Fracture: Uneven

Crystals: Triclinic, lamellar radiating to spherical aggregates

Photo by Mary Sutherland


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