Hydration Of Anhydrite: Gypsum can also form from the hydration of anhydrite (CaSO₄). Anhydrite is actually a calcium sulfate mineral that lacks the water molecules current in gypsum. When subjected to drinking water, anhydrite undergoes a hydration reaction, incorporating drinking water molecules into its structure and transforming into gypsum. Plaster: https://www.propanraya.com/id/produk/eco-gypsum-ee-4050