ralstonite
noun
ral·ston·ite
ˈrȯlztəˌnīt,
-lst-
plural -s
: a mineral NaMgAl5F12(OH)6.3H2O consisting of a hydrous basic fluoride of aluminum, sodium, and magnesium in octahedral crystals
Word History
Etymology
J. Grier Ralston, 19th century American clergyman + English -ite