What is "calcium sulphate"

Usage examples of "calcium sulphate".

It was suggested that work might be saved if only the oxygen were carried here instead of the heavy calcium sulphate, that is carry on reduction at the mine.

Among its constituents are extractive, resin (in very similar proportion), nitrogenous matter, also in small quantity, potassium chloride and calcium sulphate, and in its ashes are found iron and calcium and magnesium phosphate.