rock salt

See also: rocksalt

English

From rock +‎ salt.

rock salt (countable and uncountable, plural rock salts)

(mineralogy) The mineral halite.
- 1845, J[ohn] C[harles] Frémont, Report of the Exploring Expedition to the Rocky Mountains in the Year 1842, and to Oregon and North California in the Years 1843-’44, Washington: Gales and Seaton, →LCCN, →OCLC, page 158:
  Farther to the southward, the rivers which are affluent to the Colorado, such as the Rio Virgen, and Gila river, near their mouths, are impregnated with salt by the cliffs of rock salt between which they pass.
Coarsely ground common salt.

mineral

coarsely ground salt