Tobermorite

phyllosilicate

natrolite

Formula: Ca4Si6O17(H2O)2.(Ca.3H2O) phyllosilicate
Specific gravity: 2.40 to 2.48
Hardness: 3
Streak: White
Colour: White, pinkish white
Environments:

Metamorphic environments
Hydrothermal environments
Basaltic cavities

Tobermorite is a hydrothermal alteration product of calcium carbonate rocks, due to contact metamorphism, and it is found filling vesicles and cavities in basalt. Associated minerals include gyrolite, natrolite, zeolites, ettringite and calcite.

Localities

At Crestmore, California, USA, tobermorite is associated with blue calcite, monticellite and vesuvianite.

Common impurities: Al,Fe,Mg,Na,K,H2O

Back to Minerals