gypsum powder for cement/chalk 1)whiteness 90% above, 2)fineness of 120 ... setting 7minutes ,final setting 15 gypsum powder for cement/chalk:we are the professional manufacture for gypsum powder. we ... setting 7 minutes, Final setting for 15 minutes. Useful: cornice, chalk, ceiling, contruction, casting, wall, plasterboard, food,medical bandage ... advance after 15 days. Gypsum Powder for cement/chalk