igneous
Scoria (vesicular basalt)
Scoria; mafic volcanic rock composed mainly of plagioclase, pyroxene, and often olivine
AI-generated identification · may be incorrectDark gray to black, rough and highly vesicular, with a dull to slightly glassy luster; typically Mohs 5–6. The image shows two porous volcanic specimens, likely scoria, though the lighter piece may be a different vesicular lava.
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Physical properties
Dark gray to black, rough and highly vesicular, with a dull to slightly glassy luster; typically Mohs 5–6. The image shows two porous volcanic specimens, likely scoria, though the lighter piece may be a different vesicular lava.
Formation & geological history
Forms when gas-rich basaltic lava cools rapidly at or near the surface, trapping bubbles. It is geologically young in many volcanic regions; an exact age cannot be determined from the photo.
Uses & applications
Used as lightweight aggregate, drainage material, landscaping stone, and in abrasive or horticultural products; occasionally collected as a specimen.
Geological facts
Its holes are vesicles left by escaping volcanic gases; scoria is generally denser and darker than pumice.
Field identification & locations
Identify by its dark color, abundant rounded cavities, and rough texture; common near basaltic volcanoes and cinder cones. The photo alone cannot confirm the exact rock type or locality.
