igneous
Porous volcanic rock (likely scoria)
Scoria, vesicular basaltic to andesitic volcanic rock
AI-generated identification · may be incorrectReddish-brown, rough, and highly vesicular, with holes formed by escaping gas; typically mostly plagioclase and pyroxene, sometimes olivine, in volcanic glass. Hardness is variable, about 5–6 Mohs for its crystalline minerals; the image alone does not establish its exact composition or density.
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Physical properties
Reddish-brown, rough, and highly vesicular, with holes formed by escaping gas; typically mostly plagioclase and pyroxene, sometimes olivine, in volcanic glass. Hardness is variable, about 5–6 Mohs for its crystalline minerals; the image alone does not establish its exact composition or density.
Formation & geological history
Forms when gas-rich lava cools rapidly at or near the surface, trapping bubbles. It can form during eruptions of many ages; the specimen's age and source cannot be determined from the image.
Uses & applications
Used as lightweight landscaping aggregate, drainage material, and in some construction products; also collected as a volcanic specimen.
Geological facts
Scoria is generally denser and darker than pumice, though weathering can make it appear brown or reddish. Its cavities are called vesicles.
Field identification & locations
Look for abundant irregular gas holes and a rough volcanic texture; common around basaltic volcanic fields and cinder cones. The photo supports a scoria-like identification, but a closer view or tests would be needed to confirm it.
