metamorphic

Soapstone (talc-rich schist)

Talc schist; chiefly hydrated magnesium silicate, Mg₃Si₄O₁₀(OH)₂

AI-generated identification · may be incorrect

Very soft (Mohs 1–2), gray to greenish-gray, dull to greasy/soapy feel, with pearly surfaces and weak schistose layering; typically massive rather than visibly crystalline. Specific gravity is about 2.6–2.8.

Identified September 5, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when magnesium-rich ultramafic rocks undergo low- to medium-grade metamorphism and hydration, commonly during mountain building. Deposits range from Precambrian to younger Paleozoic–Cenozoic terrains.

Uses & applications

Used for carvings, countertops, sinks, stoves, laboratory benches, electrical insulators, and talc powder; attractive dense pieces are collectible but usually inexpensive.

Geological facts

Its defining feature is exceptional softness: it can be scratched easily with a fingernail and feels unusually smooth or greasy. The pictured specimen appears consistent with a mineral-collection soapstone/talc-schist sample.

Field identification & locations

Common in metamorphic belts and ultramafic complexes, including Brazil, India, Canada, Finland, the United States, and Zimbabwe. Confirm with a fingernail scratch, greasy feel, lack of fizz in dilute acid, and a white streak; image-based identification is not definitive.