arsoite

noun

ar·​so·​ite

ˈär(ˌ)sōˌīt

plural -s

: a dark gray porous rock consisting of trachyandesite containing phenocrysts of andesine, sanidine, diopside, and a little olivine in a trachytic groundmass of sanidine, a little oligoclase, much diopside, and magnetite

Word History

Etymology

German arsoit, from Arso, town on the island of Ischia, Italy + German -it -ite

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