igneous
Vesicular volcanic rock, likely scoria
Scoria; basaltic to andesitic volcanic rock, mainly plagioclase, pyroxene, and volcanic glass
AI-generated identification · may be incorrectDark gray-brown, highly vesicular, rough, dull-to-earthy luster, and irregular fracture; typical hardness is about 5–6 Mohs and specific gravity commonly 2.0–2.8. The image lacks enough detail for confident mineral identification.
Identified More igneous →
Explore Vesicular volcanic rock, likely scoria in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark gray-brown, highly vesicular, rough, dull-to-earthy luster, and irregular fracture; typical hardness is about 5–6 Mohs and specific gravity commonly 2.0–2.8. The image lacks enough detail for confident mineral identification.
Formation & geological history
Forms when gas-rich mafic lava erupts and rapidly cools, trapping bubbles as vesicles; it is generally geologically young and may form in cinder cones, lava flows, or volcanic bombs. Common ages range from modern eruptions to any period of volcanism.
Uses & applications
Used as lightweight aggregate, landscaping stone, drainage material, abrasives, and sometimes decorative specimens; typically has little jewelry value.
Geological facts
Scoria is denser and usually darker than pumice, which can be light-colored and float in water. Its vesicles formed from expanding dissolved volcanic gases.
Field identification & locations
Identify it by abundant holes, low density, rough texture, and a volcanic appearance; common sources include Hawaii, Iceland, the western United States, Italy, and other volcanic regions. A fresh broken surface and a magnet or density test can help distinguish basaltic scoria from slag.
