igneous
Possible vesicular volcanic rock (scoria)
Scoria; likely basaltic or andesitic, composition unconfirmed from the photo
AI-generated identification · may be incorrectDark reddish-brown, rough and porous with small cavities; likely a fine-grained volcanic groundmass. Hardness and density cannot be reliably determined visually; scoria is commonly about 5–6 Mohs and has no prominent cleavage.
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Physical properties
Dark reddish-brown, rough and porous with small cavities; likely a fine-grained volcanic groundmass. Hardness and density cannot be reliably determined visually; scoria is commonly about 5–6 Mohs and has no prominent cleavage.
Formation & geological history
Forms when gas-rich lava cools rapidly, trapping bubbles. It may be geologically recent or much older; age and exact origin cannot be established from appearance alone.
Uses & applications
Used as lightweight aggregate, drainage material, landscaping stone, and abrasive; this small irregular specimen is mainly suitable for collecting.
Geological facts
Its cavities are vesicles left by escaping volcanic gases; reddish coloring commonly results from oxidation of iron during or after cooling.
Field identification & locations
Look for a lightweight, often rough stone with abundant rounded gas holes and a volcanic texture. Similar material occurs near basaltic and andesitic volcanoes worldwide; a fresh break or density comparison would help distinguish it from other porous rocks.
