igneous
Weathered vesicular volcanic rock, likely basaltic scoria
Vesicular basalt/scoria; mainly plagioclase, pyroxene, and iron-rich glass or oxides
AI-generated identification · may be incorrectGray-green, fine-grained matrix with abundant rounded vesicles and rusty brown weathering patches; typically dull to slightly earthy luster, no obvious cleavage, hardness about 5–6, and specific gravity commonly 2.4–2.9. The green coloration may reflect chlorite or other secondary alteration minerals.
Identified More igneous →
Explore Weathered vesicular volcanic rock, likely basaltic scoria in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Gray-green, fine-grained matrix with abundant rounded vesicles and rusty brown weathering patches; typically dull to slightly earthy luster, no obvious cleavage, hardness about 5–6, and specific gravity commonly 2.4–2.9. The green coloration may reflect chlorite or other secondary alteration minerals.
Formation & geological history
An extrusive igneous rock formed when gas-rich basaltic lava cooled rapidly, trapping bubbles; later weathering and low-temperature alteration produced the green-brown surface. Such rocks are generally Cenozoic to modern, though similar textures occur throughout the geologic record.
Uses & applications
Used as lightweight aggregate, landscaping stone, road material, and occasionally as a lapidary or display specimen; usually has low jewelry value.
Geological facts
The holes are vesicles, unlike the fossil cavities or crystal pockets in many other rocks; abundant vesicles indicate lava that released gas during eruption.
Field identification & locations
Identify it by its porous basaltic texture, dark fine matrix, and rusty weathering; a streak test, fresh broken surface, and magnet test can help distinguish basalt from slag or altered volcanic rock. Common in volcanic regions worldwide, including Hawaii, Iceland, the Cascades, and continental basalt fields.
