ˈsinjəˌnīt noun
( -s )
Etymology: German syngenit, from Greek syngenēs related + German -it -ite; from its relationship to polyhalite
: a mineral K 2 Ca(SO 4 ) 2 .H 2 O consisting of a hydrous calcium potassium sulfate and occurring in colorless or white tabular crystals (hardness 2.5, specific gravity 2.6)