Talc (Silicate-Phyllosilicate)

Hardness: 1.0
Specific Gravity: 2.8

Characteristics: perfect basal cleavage; flexible fracture; resinous, silky luster and feel; translucent; often called soapstone; insoluble in most acids.

Found in schists; low temperature metamorphism of mafic rocks and dolostones.

Talc is used in ceramics, paper, paint, roofing, plastics, cosmetics; Soapstone was once used to make chemical resistant sinks and countertops for laboratories; blocks were heated on stoves and used as bed warmers.

(Primary text: Perkins, D. 2002. Mineralogy. Prentice Hall.)