igneous
Vesicular volcanic rock, likely pumice
Pumice (highly vesicular volcanic glass; composition commonly rhyolitic to andesitic)
AI-generated identification · may be incorrectPale tan, porous, dull to silky luster, and abundant rounded vesicles; hardness about 5–6, with no visible cleavage. Likely low density and may float if pores remain open.
Identified More igneous →
Explore Vesicular volcanic rock, likely pumice in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale tan, porous, dull to silky luster, and abundant rounded vesicles; hardness about 5–6, with no visible cleavage. Likely low density and may float if pores remain open.
Formation & geological history
Forms when gas-rich lava erupts explosively and rapidly cools, trapping bubbles in volcanic glass; typically Quaternary to recent, though pumice occurs throughout geologic time.
Uses & applications
Used as an abrasive, lightweight aggregate, horticultural soil additive, exfoliating stone, and concrete ingredient; this small rounded piece has negligible commercial value.
Geological facts
The specimen’s rounded shape may reflect stream, beach, or human tumbling. Its coarse, irregular pores distinguish it from smooth, uniformly porous manufactured foam.
Field identification & locations
Common near explosive volcanic centers, including Iceland, Italy, Japan, Indonesia, Mexico, New Zealand, and the western United States. Confirm by testing whether it is unusually lightweight, scratches glass only weakly, and has a glassy porous interior.
