igneous
Pumice
Pumice (volcanic glass foam)
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, grayish-white to off-white color, dull to earthy luster, amorphous volcanic glass structure, specific gravity around 0.25 to 0.9 (floats on water).
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Physical properties
Hardness of 6 on the Mohs scale, grayish-white to off-white color, dull to earthy luster, amorphous volcanic glass structure, specific gravity around 0.25 to 0.9 (floats on water).
Formation & geological history
Formed through the very rapid cooling of frothy, gas-rich felsic lava during explosive volcanic eruptions.
Uses & applications
Used in lightweight concrete, abrasive stones, exfoliating cosmetic products, and gardening soil amendments.
Geological facts
Pumice is the only rock that can float on water due to its extremely high vesicular porosity filled with trapped gases.
Field identification & locations
Easily identified by its extremely low density, rough vesicular texture, and pale color; commonly found near active or historical volcanic regions worldwide.
