igneous
Pumice
Pumice (volcanic glass foam)
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically light gray to white, dull luster, amorphous glassy structure, exceptionally low specific gravity allowing it to float on water.
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Physical properties
Hardness of 6 on the Mohs scale, typically light gray to white, dull luster, amorphous glassy structure, exceptionally low specific gravity allowing it to float on water.
Formation & geological history
Formed during explosive volcanic eruptions when frothy, gas-rich lava rapidly cools and depressurizes, trapping gas bubbles within the glass matrix.
Uses & applications
Used widely in lightweight concrete, abrasive soaps, pumice stones for personal care, and horticulture as a soil amendment.
Geological facts
Pumice is one of the only rocks that can float on water due to its high porosity and trapped internal gas bubbles.
Field identification & locations
Easily identified by its extremely light weight, pale color, and vesicular texture filled with small gas cavities; found worldwide near active or ancient volcanic regions.
