igneous
Pumice
Pumice (volcanic glass / felsic extrusive rock)
AI-generated identification · may be incorrectMohs hardness 6, white to grey color, dull to earthy luster, amorphous volcanic glass with vesicular (frothy) crystal structure, specific gravity less than 1.0 (floats on water).
Identified More igneous →
Explore Pumice in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness 6, white to grey color, dull to earthy luster, amorphous volcanic glass with vesicular (frothy) crystal structure, specific gravity less than 1.0 (floats on water).
Formation & geological history
Formed through the rapid solidification and depressurization of frothy, gas-rich felsic lava during explosive volcanic eruptions.
Uses & applications
Widely used in lightweight concrete aggregates, abrasive cosmetics, horticulture, and stone-washing fabrics.
Geological facts
Pumice is one of the only rocks that can float on water due to its high density of trapped gas bubbles.
Field identification & locations
Easily identified in the field by its extreme lightness, pale color, and extensive vesicular texture; found near active or historical volcanic regions worldwide.
