igneous
Vesicular volcanic rock, likely pumice or scoriaceous basalt
Highly vesicular basaltic–andesitic volcanic rock; chiefly plagioclase, pyroxene, and volcanic glass
AI-generated identification · may be incorrectHardness about 5–6 (occasionally softer if glass-rich); gray-brown, porous, dull to slightly glassy, with abundant irregular gas cavities and no obvious cleavage. The rough, lightweight texture suggests pumice/scoria, though the dark coloration favors scoria or weathered vesicular basalt.
Identified More igneous →
Explore Vesicular volcanic rock, likely pumice or scoriaceous basalt in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 5–6 (occasionally softer if glass-rich); gray-brown, porous, dull to slightly glassy, with abundant irregular gas cavities and no obvious cleavage. The rough, lightweight texture suggests pumice/scoria, though the dark coloration favors scoria or weathered vesicular basalt.
Formation & geological history
Formed when gas-rich lava erupted and rapidly cooled, trapping bubbles; likely Cenozoic or younger, with age impossible to determine from the image. Common in lava flows, cinder cones, and volcanic bombs.
Uses & applications
Used as lightweight aggregate, abrasive, landscaping stone, and occasionally as a decorative specimen; typically not suitable for jewelry.
Geological facts
Vesicles are frozen gas bubbles, and their abundance records volatile-rich magma and rapid decompression during eruption.
Field identification & locations
Common worldwide in volcanic regions, including Iceland, Italy, Japan, Mexico, and the western United States. Field identification relies on abundant cavities, a volcanic texture, and low density; pumice may float, whereas basaltic scoria generally sinks.
