GreenCal gypsum powder is a natural 98% pure calcium sulphate dihydrate. GreenCal gypsum powder is mined and then milled to a 45 to 75 micron powder (95% passing through 45 micron). The very high purity and ultra fine particle size of GreenCal gypsum powder make it readily available. GreenCal gypsum powder is used in the manufacturing of stock and animal feed products.