ˈpaknəˌlīt noun
( -s )
Etymology: German pachnolit, from Greek pachnē hoarfrost + German -lit -lite; akin to Greek pēgnynai to fasten together — more at pact
: a mineral NaCaAlF 6 .H 2 O consisting of a hydrous fluoride of sodium, calcium, and aluminum occurring in colorless to white monoclinic crystals (hardness 3, specific gravity 3)