![11 Hardest Minerals In The World | On Mohs Scale](/3wzg0da/680.jpg)
11 Hardest Minerals In The World | On Mohs Scale
· 10. Gypsum. Gypsum found in Poland. Mohs hardness: 2. Absolute hardness: 3. Chemical formula: CaSO 4 ·2H 2 O. Gypsum is a sulfate mineral composed of calcium sulfate dihydrate. It is widely mined and used to manufacture cement, plaster of .