Douglas Harper's Etymology Dictionary
Usage examples of "rock-salt".
Mines of great value exist in the Ural, Obdorsk and Altai mountains, which produce gold, copper, iron, silver, platinum, rock-salt, marble and kaolin or china clay.
Mines of great value exist in the Ural, Obdorsk and Altai mountains, which produce gold, copper, iron, silver, platinum, rock-salt, marble and kaolin or china clay.