igneous
Vesicular basalt (scoria-like volcanic rock)
Basalt; primarily plagioclase, clinopyroxene, and olivine, with abundant vesicles
AI-generated identification · may be incorrectDark gray to black, fine-grained and commonly vesicular, with dull to slightly glassy luster; Mohs hardness about 5–6, no obvious cleavage, and specific gravity roughly 2.6–3.0. The porous texture indicates gas bubbles trapped during cooling.
Identified More igneous →
Explore Vesicular basalt (scoria-like volcanic rock) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark gray to black, fine-grained and commonly vesicular, with dull to slightly glassy luster; Mohs hardness about 5–6, no obvious cleavage, and specific gravity roughly 2.6–3.0. The porous texture indicates gas bubbles trapped during cooling.
Formation & geological history
An extrusive igneous rock formed when mafic lava cooled rapidly at or near Earth’s surface; commonly Quaternary to Recent, though basalt occurs throughout geologic time. The holes formed from escaping volcanic gases.
Uses & applications
Used as lightweight aggregate, landscaping stone, road base, and occasionally abrasive or decorative material; typically has little jewelry value.
Geological facts
Scoria is the more vesicular, generally darker and denser counterpart to pumice. Basalt is the most widespread volcanic rock and forms much of the oceanic crust.
Field identification & locations
Identify it by its dark color, fine texture, iron-rich appearance, and gas cavities; a magnet may show weak attraction. Common in volcanic regions, especially Hawaii, Iceland, the Cascades, and oceanic islands.
