Pantellerite

Pantellerite is a type of volcanic rock, specifically a peralkaline rhyolite. It has a higher iron and lower aluminium composition than comendite.[1] It is named after Pantelleria, a volcanic island in the Strait of Sicily and the type location for this rock. On Pantelleria the rock is usually found as a vitrophyre containing phenocrysts of anorthoclase or sanidine. Quartz is found only in the most strongly peralkaline rocks. Mafic minerals may include aegirine, fayalite, aenigmatite, ilmenite, and sodic amphibole (often arfvedsonite or ferrorichterite).[2]

Thin section of ignimbrite of pantelleritic composition from Pantelleria, Italy

References

1. Dictionary of Mining, Mineral, and Related Terms: Pantellerite Archived 2008-04-20 at the Wayback Machine
2. White, J.C., Ren, M., and Parker, D.F., 2005, "Variation in mineralogy, temperature, and oxygen fugacity in a suite of strongly peralkaline lavas and tuffs, Pantelleria, Italy." The Canadian Mineralogist, vol. 43, 1331-1347.