Pantellerite
“The most extreme volcanic glass”
Pantellerite is a rare, highly peralkaline volcanic rock — a type of rhyolite extremely enriched in sodium and potassium relative to aluminum. Named after the Italian island of Pantelleria, it represents some of the most chemically extreme compositions found in volcanic rocks on Earth.
alkali feldspar, quartz, aegirine, aenigmatite, fayalite, volcanic glass
Pantelleria (Italy), Erta Ale (Ethiopia), Menengai (Kenya), Terceira (Azores), Mayor Island (New Zealand)
6-6.5
Pantellerite is so alkali-rich that its lava can be unusually fluid for a silica-rich magma — behaving more like basalt than the thick, sticky rhyolite you'd expect.
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What makes pantellerite's physical behaviour unusual for a silica-rich volcanic rock?
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