Pumice

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Specimen o heichly porous pumice frae Teide volcano on Tenerife, Canary Islands. Density o specimen approximately 0.25 g/cm3; scale in centimeters.

Pumice /ˈpʌms/, cried pumicite in its powdered or dust form, is a volcanic rock that consists o heichly vesicular rough texturt volcanic gless, which mey or mey nae contain crystals.