igneous
Small vesicular volcanic rock, likely scoria
Scoria; predominantly basaltic to andesitic volcanic rock
AI-generated identification · may be incorrectDark reddish-brown, porous, and dull to slightly glassy; composed mainly of plagioclase, pyroxene, and iron-rich volcanic glass. Typical hardness is about 5–6 Mohs, with low density due to abundant gas vesicles; exact identification is limited by the specimen’s tiny size and image.
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Physical properties
Dark reddish-brown, porous, and dull to slightly glassy; composed mainly of plagioclase, pyroxene, and iron-rich volcanic glass. Typical hardness is about 5–6 Mohs, with low density due to abundant gas vesicles; exact identification is limited by the specimen’s tiny size and image.
Formation & geological history
Forms when gas-rich basaltic or andesitic lava rapidly cools at or near a volcanic vent, preserving bubbles. It may range from modern eruptions to rocks millions of years old, depending on locality.
Uses & applications
Used as lightweight aggregate, landscaping stone, drainage material, and abrasive; generally not used as a gemstone.
Geological facts
The reddish color commonly results from oxidation of iron during or after eruption. Its vesicles distinguish scoria from dense basalt, while very pale, highly frothy material would more likely be pumice.
Field identification & locations
Look for abundant irregular pores, a rough surface, dark volcanic color, and light weight; common around cinder cones, lava fields, and volcanic islands. A definitive identification would require a closer view and locality information.
