malladrite
noun
mal·la·drite
məˈläˌdrīt,
ˈmaləˌd-
plural -s
: a sodium fluosilicate Na2SiF6 occurring in minute hexagonal crystals in fumaroles in the crater of Vesuvius near Naples in Italy
Word History
Etymology
Italian, from Alessandro Malladra †1944 Italian geologist + Italian -ite