igneous
Pumice
Pumice (Volcanic Glass Foam)
AI-generated identification · may be incorrectMohs hardness 6, light gray to white color, vitreous to dull luster, amorphous volcanic glass structure, specific gravity less than 1.0 allowing it to float on water.
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Physical properties
Mohs hardness 6, light gray to white color, vitreous to dull luster, amorphous volcanic glass structure, specific gravity less than 1.0 allowing it to float on water.
Formation & geological history
Formed during explosive volcanic eruptions when gas-rich felsic lava rapidly cools and depressurizes, trapping gas bubbles.
Uses & applications
Used in lightweight concrete, landscaping, abrasive soaps, personal care pumice stones, and horticulture.
Geological facts
Pumice is one of the few natural rocks that can float on water due to its extremely high vesicular porosity.
Field identification & locations
Easily identified by its extremely low weight, pale color, and abundant vesicular pores; found globally near active and ancient volcanic arcs.
