igneous
Scoria (vesicular volcanic rock)
Basaltic or andesitic scoria; chiefly plagioclase, pyroxene, and iron-rich volcanic glass
AI-generated identification · may be incorrectDark brown to black, rough and highly vesicular, with a generally dull to subvitreous luster; hardness about 5–6 Mohs. The image’s pores and shape suggest scoria, though a photo cannot confirm composition.
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Physical properties
Dark brown to black, rough and highly vesicular, with a generally dull to subvitreous luster; hardness about 5–6 Mohs. The image’s pores and shape suggest scoria, though a photo cannot confirm composition.
Formation & geological history
Forms when gas-rich lava cools rapidly, trapping bubbles; typically produced by young volcanic eruptions, from recent to geologically ancient deposits.
Uses & applications
Used as lightweight aggregate, landscaping stone, drainage material, and sometimes in abrasives or decorative crafts.
Geological facts
Scoria’s abundant gas cavities make it lighter than dense lava, though it is usually not as light as pumice.
Field identification & locations
Look for a dark, rough surface with many rounded or irregular holes; common near cinder cones and basaltic volcanoes worldwide. The pictured specimen appears consistent with scoria.
