We are offering gypsum in two varieties - natural and calcined. The pure calcium sulfate (gypsum) is an excellent source of calcium. It is commonly used to make tofu and is also used for gardening, among other purposes. These products are absolutely preservative free, and contain 23% of calcium with high quality and purity. Talking about the uses of gypsum, these are used in baking, winemaking, and brewing. Their hardness can be increased by the addition of water in a specific amount. A few other uses of gypsum are in the construction to make plasters, molds, and casts.