igneous
Porous volcanic rock, likely scoria
Scoria (vesicular basaltic to andesitic volcanic rock)
AI-generated identification · may be incorrectCoarse, highly vesicular texture with tan-brown weathered surfaces and dark mineral grains; likely plagioclase, pyroxene, and possibly olivine. Hardness varies with composition, roughly 5–6 Mohs; generally dull to slightly glassy, with no consistent cleavage.
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Physical properties
Coarse, highly vesicular texture with tan-brown weathered surfaces and dark mineral grains; likely plagioclase, pyroxene, and possibly olivine. Hardness varies with composition, roughly 5–6 Mohs; generally dull to slightly glassy, with no consistent cleavage.
Formation & geological history
Forms when gas-rich lava cools rapidly, trapping bubbles; commonly produced by eruptions ranging from recent to ancient, with age undeterminable from the image.
Uses & applications
Used as lightweight aggregate, drainage or landscaping material, and occasionally in decorative rockwork.
Geological facts
The rounded holes are vesicles left by escaping volcanic gases; scoria is typically denser than pumice and often dark, though weathering can make it rusty tan.
Field identification & locations
Look for abundant cavities, a rough texture, and a relatively heavy feel compared with pumice. Common near basaltic volcanic fields and cinder cones; this small specimen has no distinctive locality clues.
