Soapstone / Steatite

Physical Properties

Hardness: 1.0–2.5 (Mohs scale), Color: Grey, greenish-grey, or bluish-grey, Lustre: Greasy to pearly, Crystal structure: Monoclinic/Triclinic (massive form), Cleavage: Perfect basal (though often massive), Specific gravity: 2.7–2.8

Formation & Geological History

Formed through the regional or contact metamorphism of ultramafic igneous rocks (like peridotite or dunite) or impure dolostones, specifically via hydrothermal alteration (steatitization).

Uses & Applications

Used for 'whiskey stones' (chilling drinks without dilution), countertops, wood-burning stoves, carved sculptures, and electrical insulators due to its high heat capacity and chemical resistance.

Geological Facts

Because of its high talc content, soapstone feels 'soapy' or slippery to the touch. It has been used for over 3,000 years by many cultures, including Native Americans, for making bowls and pipes because it is easy to carve and retains heat.

Field Identification & Locations

Identify in the field by its soapy texture and its extreme softness; it can be easily scratched by a fingernail. It is common in metamorphic belts like the Appalachian Mountains, Brazil, and Scandinavia.

Identified on: 4/20/2026

Mode: Standard