metamorphic
Soapstone
Steatite (composed primarily of Talc, Mg3Si4O10(OH)2)
Hardness: 1.0 - 2.5 on Mohs scale (can be scratched with a fingernail); Color: shades of gray, green, brown, or reddish-tan due to iron oxidation; Luster: greasy to pearly; Structure: massive/foliated; soapy or slick feel.
- Hardness
- 1
- Luster
- greasy to pearly
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 1.0 - 2.5 on Mohs scale (can be scratched with a fingernail); Color: shades of gray, green, brown, or reddish-tan due to iron oxidation; Luster: greasy to pearly; Structure: massive/foliated; soapy or slick feel.
Formation & geological history
Formed through the regional or contact metamorphism of ultramafic igneous rocks (like peridotite) or siliceous dolostones in subduction zones or mountain-building environments. Ages vary from Precambrian to Cenozoic.
Uses & applications
Used for decorative carvings, sculptures, kitchen countertops, wood-burning stoves (due to high heat capacity), and electrical insulators.
Geological facts
Soapstone is naturally acid and heat resistant. It has been used for over 3,000 years by various cultures for cooking vessels and seals because it is easy to carve and retains heat exceptionally well.
Field identification & locations
Identify by its 'soapy' feel and very low hardness. It is commonly found in metamorphic belts in Brazil, India, China, Finland, and the USA (Appalachia). Collectors should look for smoothness and the absence of sharp mineral grains.
More like this
