Pumice Is The Only Rock That Floats
It can form floating islands the size of Belgium.
Reviewed by the CurioVault curator · 8 October 2026 · Editorial standards
Pumice forms when volcanic lava cools so fast that gas bubbles are trapped, making it 90% air. It floats. In 2012, an underwater eruption near New Zealand created a pumice raft 400km long — larger than Belgium — drifting for months. Sailors thought it was a new island. Birds landed on it. It eventually dispersed, carrying marine life to new reefs.
Sources & Further Reading
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