igneous
Vesicular volcanic rock, likely scoria
Scoria (vesicular basaltic to andesitic volcanic rock)
AI-generated identification · may be incorrectBrown-gray, dull to slightly glassy, with abundant rounded gas cavities; typically hardness about 5–6, composed mainly of plagioclase, pyroxene, and volcanic glass. The image alone cannot confirm composition; the specimen could also be vesicular slag.
Identified More igneous →
Explore Vesicular volcanic rock, likely scoria in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Brown-gray, dull to slightly glassy, with abundant rounded gas cavities; typically hardness about 5–6, composed mainly of plagioclase, pyroxene, and volcanic glass. The image alone cannot confirm composition; the specimen could also be vesicular slag.
Formation & geological history
Forms when gas-rich lava cools rapidly at or near the surface, trapping bubbles; commonly associated with relatively young volcanic eruptions.
Uses & applications
Scoria is used as lightweight aggregate, landscaping stone, drainage material, and abrasive; small specimens are collected for their vesicular texture.
Geological facts
Its holes are vesicles left by escaping volcanic gases. Scoria is generally denser and darker than pumice, which may float when dry.
Field identification & locations
Look for irregular, interconnected gas cavities and a dark, earthy volcanic surface; common near cinder cones and basaltic volcanoes. A photo cannot distinguish natural scoria from industrial slag with certainty.
