pachnolite
/ˈpaknə(ʊ)lʌɪt/Mineralogy
noun
A hydrated fluoride of aluminium, calcium, and sodium, NaCaAlF6·H2O, occurring as small white monoclinic crystals on cryolite.
Origin
Mid 19th century; earliest use found in American Journal of Science. From German Pachnolith from ancient Greek πάχνη hoar frost + German -lith.