igneous
Pumice
Felsic volcanic rock
AI-generated identification · may be incorrectHardness 5.5 to 6, colors range from white to gray and yellowish-brown, dull luster, amorphous glassy texture with abundant vesicular pores, extremely low specific gravity allowing it to float on water.
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Physical properties
Hardness 5.5 to 6, colors range from white to gray and yellowish-brown, dull luster, amorphous glassy texture with abundant vesicular pores, extremely low specific gravity allowing it to float on water.
Formation & geological history
Formed during explosive volcanic eruptions when gas-rich, frothy felsic lava cools rapidly and depressurizes.
Uses & applications
Widely used in lightweight construction aggregates, abrasive soaps, cosmetic exfoliating stones, and horticulture.
Geological facts
Pumice is one of the only rocks that can float on water due to its high concentration of trapped gas bubbles.
Field identification & locations
Easily identified by its extremely lightweight feel, numerous tiny air cavities, and light color; found globally near active and ancient volcanic regions.
