igneous
Pumice
Pumice (Volcanic Rock)
Hardness: 6 on the Mohs scale, Color: White, off-white, gray, or yellowish, Luster: Dull to earthy, Crystal Structure: Amorphous (glassy foam structure with numerous gas cavities)
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Physical properties
Hardness: 6 on the Mohs scale, Color: White, off-white, gray, or yellowish, Luster: Dull to earthy, Crystal Structure: Amorphous (glassy foam structure with numerous gas cavities)
Formation & geological history
Formed from rapidly cooling, frothy felsic or intermediate volcanic lava containing high amounts of gas and water vapor, trapping gas bubbles as it solidifies.
Uses & applications
Used in lightweight construction materials, concrete aggregates, abrasives in personal care products, polishing stones, and horticulture.
Geological facts
Pumice is famous for being the only known rock that can float on water due to its extremely high porosity and trapped gas bubbles.
Field identification & locations
Easily identified by its very light weight, porous sponge-like texture, and pale coloration. Common near young volcanic regions and deposits worldwide.
