Definition of muriacite in US English:

muriacite

noun

Mineralogy
historical
  • Anhydrous gypsum (anhydrite) in a crystalline form.

Origin

Late 18th century; earliest use found in Richard Kirwan (1733–1812), chemist and mineralogist. From German Muriacit from classical Latin muria + German -it (so called because the mineral was originally thought to be muriated lime); the interpolated -c- is unexplained.