Pumice
“The rock that floats”
Igneous
Pumice is an extremely porous volcanic rock formed when gas-rich lava is ejected from a volcano and cools rapidly in the air. Its countless tiny air pockets make it light enough to float on water — one of the only rocks that can.
Composition
volcanic glass, feldspar, quartz (amorphous)
Where Found
Lipari (Italy), Kamchatka (Russia), Oregon (USA), Greece, New Zealand
Mohs Hardness
6
Fun Fact
In 2012, a pumice raft the size of Belgium was spotted floating in the Pacific Ocean after an underwater volcanic eruption near New Zealand.
Test Your Knowledge
What volatile substance is primarily responsible for creating pumice's vesicular texture?
Related Specimens
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