pantellerite
/panˈtɛlərʌɪt/Geology
noun
A peralkaline variety of rhyolite containing phenocrysts of anorthoclase, cossyrite, and other minerals in a dark green to black groundmass.
Origin
Late 19th century; earliest use found in The Century Dictionary. From Italian pantellerite from Pantelleria, the name of an island in the Mediterranean between Sicily and the coast of Tunisia where the rock was first identified + -ite.