igneous
Likely pumice or vesicular volcanic rock
Pumice; predominantly volcanic glass (silica-rich, commonly rhyolitic or dacitic)
AI-generated identification · may be incorrectPale gray-white, porous, and dull to slightly glassy; hardness about 5–6 Mohs, with abundant vesicles and very low density. The specimen appears irregular and may float if sufficiently porous.
Identified More igneous →
Explore Likely pumice or vesicular volcanic rock in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray-white, porous, and dull to slightly glassy; hardness about 5–6 Mohs, with abundant vesicles and very low density. The specimen appears irregular and may float if sufficiently porous.
Formation & geological history
Forms when gas-rich explosive magma rapidly decompresses and quenches, trapping bubbles in volcanic glass; typically Quaternary to recent, though older deposits are widespread.
Uses & applications
Used as an abrasive, lightweight aggregate, concrete additive, horticultural soil amendment, and cosmetic exfoliant; attractive pieces may be collected but have modest value.
Geological facts
Pumice is not crystalline like most rocks; its vesicles record escaping volcanic gases. A closely related, darker and denser material could be scoria, but this specimen’s light color favors pumice.
Field identification & locations
Common around explosive volcanic regions, including Italy, Greece, Turkey, Japan, New Zealand, Mexico, and the western United States. Confirm by testing low density, porous texture, and lack of reaction to dilute acid.
