igneous
Vesicular volcanic rock, likely scoria
Scoria (vesicular basalt or andesite; exact composition cannot be confirmed from the image)
AI-generated identification · may be incorrectDark reddish-brown, rough and porous, with abundant gas-bubble cavities; typically glassy to dull, with hardness about 5–6 on the Mohs scale. Its crystals are too fine to identify visually; specific gravity is relatively low for a solid rock but usually greater than pumice.
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Physical properties
Dark reddish-brown, rough and porous, with abundant gas-bubble cavities; typically glassy to dull, with hardness about 5–6 on the Mohs scale. Its crystals are too fine to identify visually; specific gravity is relatively low for a solid rock but usually greater than pumice.
Formation & geological history
Forms when gas-rich lava cools quickly, trapping bubbles; commonly produced by cinder cones and lava flows. The specimen’s geological age and precise formation setting cannot be determined from the image.
Uses & applications
Used as lightweight aggregate, landscaping stone, drainage material, and sometimes abrasive; attractive pieces are collected or used decoratively.
Geological facts
Scoria is generally denser and darker than pumice and may sink in water. Its reddish color commonly comes from iron oxidation.
Field identification & locations
Look for a dark, iron-rich volcanic rock with numerous irregular vesicles; common around basaltic volcanoes and cinder cones worldwide. A photo alone cannot establish the exact rock type or locality.
