Occurrence of calcium sulfate
Gypsum can be found almost anywhere worldwide and is obtained by mining or quarrying. It mostly mined in the US, Europe, England, Canada, India and some African countries. It can also be created in your kitchen(see video)
Uses
Calcium sulfate is commonly used to make plaster of Paris. It is also used as a pigment in white paint, in cement, as a sizer and filler for paper, as a drying agent and is even used as a fertilizer. Its most interesting use in my opinion is its use in making tofu.