Go Deeper For parents & teachers
A highly vesicular volcanic rock, formed when gas-rich lava is ejected explosively and the sudden pressure drop causes the dissolved gases to expand rapidly into a solidified froth. Densities below water's are routine, making pumice the only rock that commonly floats. After submarine eruptions, giant pumice rafts have been observed drifting thousands of kilometres across the Pacific. Industrial uses range from abrasives and horticultural substrate to ingredients in lightweight concrete.
Appears In
The Burning Mountain Chapter 11 — The Lake That Boiled
"Sketch, carrying the mapping frame and folding measuring rods, stepped carefully over a cracked patch of pumice. "The shoreline moved three times since first light.""
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