igneous
Pumice
Vesicular Felsic Extrusive Igneous Rock
Hardness 5-6 (Mohs scale), porous texture with visible vesicles, light brown/grey to buff color, earthy to glassy luster, highly buoyant due to air pockets.
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Physical properties
Hardness 5-6 (Mohs scale), porous texture with visible vesicles, light brown/grey to buff color, earthy to glassy luster, highly buoyant due to air pockets.
Formation & geological history
Formed during explosive volcanic eruptions when highly gas-charged, viscous magma is rapidly cooled and depressurized, trapping gas bubbles within the glass matrix.
Uses & applications
Used as an abrasive in cosmetic products (pedicure stones), lightweight concrete aggregate, soil conditioner, and industrial polishing.
Geological facts
Pumice is one of the few rocks that can float on water until it becomes waterlogged. Massive raft formations of pumice can travel across oceans after subsea volcanic eruptions.
Field identification & locations
Identified by its extremely light weight, spongy or porous vesicular appearance, and rough abrasive texture. Commonly found in volcanic regions near active or ancient explosive volcanoes.
