igneous
Pumice
Pumice
Hardness of 6 on Mohs scale (for the glass framework), color ranges from white, gray, yellowish, to brown, dull to earthy luster, amorphous volcanic glass structure, specific gravity less than 1 (often floats on water).
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Physical properties
Hardness of 6 on Mohs scale (for the glass framework), color ranges from white, gray, yellowish, to brown, dull to earthy luster, amorphous volcanic glass structure, specific gravity less than 1 (often floats on water).
Formation & geological history
Formed from explosive volcanic eruptions where gas-rich, felsic to intermediate lava rapidly cools and depressurizes, trapping gas bubbles within the glassy matrix.
Uses & applications
Used in abrasive materials, lightweight construction aggregates, concrete additives, exfoliating personal care products, and horticulture.
Geological facts
Pumice is one of the few rocks that can float on water due to its extremely high porosity and trapped gas bubbles.
Field identification & locations
Easily identified by its extremely lightweight feel, pale color, and abundant vesicular (bubble) texture. Found near volcanic regions worldwide.
