igneous
Vesicular volcanic rock, possibly weathered basalt or scoria
Basaltic scoria/vesicular basalt; predominantly plagioclase, pyroxene, and iron-titanium oxides
AI-generated identification · may be incorrectDark gray to black, highly vesicular, rough and irregular with dull to locally glassy luster; hardness about 5–6 Mohs, no obvious cleavage, and typically fine-grained crystalline or partly glassy texture. The pale yellow-brown material is likely weathering, secondary minerals, or adhering matrix.
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Physical properties
Dark gray to black, highly vesicular, rough and irregular with dull to locally glassy luster; hardness about 5–6 Mohs, no obvious cleavage, and typically fine-grained crystalline or partly glassy texture. The pale yellow-brown material is likely weathering, secondary minerals, or adhering matrix.
Formation & geological history
Forms when gas-rich mafic lava cools rapidly at or near a volcanic vent, commonly during the Quaternary or younger volcanic activity. Exact identification and age require fresh-surface examination and locality data.
Uses & applications
Used as lightweight aggregate, landscaping stone, abrasive, and sometimes in horticulture; generally unsuitable for jewelry except as a decorative specimen.
Geological facts
Vesicles are trapped gas bubbles, and their abundance can make the rock unusually light. A magnet may respond weakly because of magnetite or other iron oxides.
Field identification & locations
Common in basaltic volcanic fields, cinder cones, and lava flows worldwide; identify by dark mafic color, abundant holes, and low density. The image alone cannot distinguish scoria confidently from heavily weathered vesicular basalt.
