Density And Certain Gravity: Density refers back to the mass per unit quantity of the compound, though particular gravity compares a mineral's density on the density of water. Gypsum occurs in in depth beds associated with other evaporite minerals (e.g., anhydrite and halite), significantly in Permian and Triassic sedimentary formations; https://www.propanraya.com/id/produk/eco-gypsum-ee-4050