Gypsum wallboard (drywall or plaster board) , is a building panel consisting mainly of a gypsum core material sandwiched between two durable paper faces.
Gypsum, a soft mineral (calcium sulphate dihydrate) is used by cement manufacturers to retard and regulate the set of Portland cement. Gypsum rock not only enhances the strength of cement but also reduces shrinkage of cured cement.
Soil conditioner / fertilizer
Gypsum is also used as an economical soil conditioner and fertilizer in some crops.