igneous
Vesicular basalt (scoria-like volcanic rock)
Vesicular basalt; predominantly plagioclase, pyroxene, and olivine with iron-rich volcanic glass
AI-generated identification · may be incorrectDark reddish-brown, fine-grained, porous, and dull to slightly glassy; typically Mohs 5–6, with small gas vesicles and no obvious cleavage. The red color commonly reflects oxidation of iron minerals.
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 reddish-brown, fine-grained, porous, and dull to slightly glassy; typically Mohs 5–6, with small gas vesicles and no obvious cleavage. The red color commonly reflects oxidation of iron minerals.
Formation & geological history
An extrusive mafic igneous rock formed when basaltic lava cooled rapidly at or near the surface, trapping gas bubbles; likely Quaternary or younger, though precise age cannot be determined from the image.
Uses & applications
Used as lightweight aggregate, landscaping stone, abrasives, and occasionally in construction; generally low jewelry value, though attractive pieces are collected.
Geological facts
Its vesicles distinguish it from dense basalt, while its relatively low porosity compared with pumice suggests scoria or vesicular basalt rather than highly frothy pumice.
Field identification & locations
Identify it by its rusty-red to black color, fine texture, and rounded holes; common in volcanic fields, lava flows, and cinder cones worldwide, including Iceland, the western United States, Mexico, and Italy.
