硬石膏 Traditional form: 硬石膏 Pinyin (reading): yìngshígāo Definitions: anhydrite CaSO4 Characters: 硬 - firm, hard, strong; obstinate 石 - stone, rock, mineral 膏 - grease, fat; ointment, paste Traditional characters: 硬 - firm, hard, strong; obstinate 石 - stone, rock, mineral 膏 - grease, fat; ointment, paste