igneous
Likely scoria (vesicular basalt)
Scoria, typically basaltic; composed mainly of plagioclase, pyroxene, and sometimes olivine
AI-generated identification · may be incorrectDark, rough, and strongly vesicular, with a dull to subvitreous luster. Hardness is typically about 5–6 on the Mohs scale; the image does not establish its density or exact mineral composition.
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Physical properties
Dark, rough, and strongly vesicular, with a dull to subvitreous luster. Hardness is typically about 5–6 on the Mohs scale; the image does not establish its density or exact mineral composition.
Formation & geological history
Forms when gas-rich basaltic lava cools quickly, trapping bubbles. It is generally geologically young, associated with volcanic eruptions and cinder cones.
Uses & applications
Used as lightweight landscaping stone, drainage aggregate, and construction fill; attractive pieces may be collected or used decoratively.
Geological facts
Scoria’s abundant gas cavities distinguish it from many dense basalts, though this specimen’s unusually uniform, shaped appearance means identification from the photo alone is uncertain.
Field identification & locations
Look for a naturally irregular, lightweight volcanic rock with many cavities; common around basaltic volcanoes worldwide. The displayed form could be shaped or processed, and a photo cannot rule out an imitation.
