Difference Between Gypsum and Limestone Compare the
Nov 04 2011· The key difference between gypsum and limestone is that the calcium sulfate is the main constituent in gypsum whereas calcium carbonate is the main constituent of limestone Limestone and gypsum are minerals that form from calcium salts limestone contains calcium carbonate while gypsum contains CaSO 4 ·2H 2 O However their properties and usages are different from each other