igneous
Vesicular volcanic scoria (likely weathered basaltic scoria)
Scoria; chiefly vesicular basalt, composed mainly of plagioclase, pyroxene, and iron-rich glass
AI-generated identification · may be incorrectHardness about 5–6 Mohs; gray-brown, highly porous, dull to slightly glassy luster, with abundant rounded gas vesicles and no prominent cleavage. Typically has low density and rough, frothy surfaces.
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Physical properties
Hardness about 5–6 Mohs; gray-brown, highly porous, dull to slightly glassy luster, with abundant rounded gas vesicles and no prominent cleavage. Typically has low density and rough, frothy surfaces.
Formation & geological history
Forms when gas-rich basaltic lava erupts and rapidly cools, trapping bubbles; commonly Quaternary to modern volcanic material. The specimen appears strongly weathered or coated by secondary minerals.
Uses & applications
Used as lightweight aggregate, drainage and landscaping stone, abrasive material, and occasionally as a decorative or craft stone. Common specimens generally have little jewelry value.
Geological facts
Scoria is darker and denser than pumice because it contains more iron and crystallized basaltic minerals; pale weathering can obscure its original color.
Field identification & locations
Identify it by its irregular vesicles, lightweight feel, rough texture, and volcanic appearance; unlike slag, natural scoria usually lacks metallic droplets or strongly artificial textures. Common around cinder cones and basaltic volcanic fields worldwide.
