prosopite
noun
pros·o·pite
ˈpräsəˌpīt
plural -s
: a mineral CaAl2(F,OH)8 consisting of a basic fluoride of calcium and aluminum
Word History
Etymology
German prosopit, from prosop- (from Greek prosōpeion mask, from prosōpon face) + -it -ite; from its occurrence as a pseudomorph