igneous
Iron-rich, vesicular volcanic rock (possibly scoria)
Scoria, likely basaltic; exact identification requires examination and testing
AI-generated identification · may be incorrectRough, porous, dark brown to rusty orange from iron-oxide weathering; likely mostly volcanic glass and plagioclase with pyroxene and iron oxides. Scoria is typically about 5–6 on the Mohs scale, with a fine-grained to glassy texture and no prominent cleavage; the pictured specimen is weathered and details are unclear.
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Physical properties
Rough, porous, dark brown to rusty orange from iron-oxide weathering; likely mostly volcanic glass and plagioclase with pyroxene and iron oxides. Scoria is typically about 5–6 on the Mohs scale, with a fine-grained to glassy texture and no prominent cleavage; the pictured specimen is weathered and details are unclear.
Formation & geological history
Forms when gas-rich basaltic lava cools rapidly, trapping bubbles; the rusty surface suggests later oxidation. Such rocks form in volcanic eruptions, generally in geologically recent or ancient volcanic settings.
Uses & applications
Scoria is used as lightweight aggregate, landscaping stone, and abrasive; this irregular specimen is mainly of modest collector interest.
Geological facts
Its abundant cavities (vesicles) record gas bubbles in lava; scoria is generally denser and darker than pumice.
Field identification & locations
Look for a lightweight, dark, strongly vesicular texture and often reddish-brown iron staining; common near basaltic volcanoes and cinder cones. The photo alone cannot confirm scoria or distinguish it from other iron-rich porous rocks.
