Gypsum Mineral:

Chemical name is calcium sulfate dehydrate, formula is CaSO4•2H2O.
Gypsum makes an ideal building material because it is abundant, economical, fire resistant, strong, and versatile.

Some of the main uses:

• chalk for blackboards
• in cement
• to make drywall
• a construction material plaster
• dental molds
• surgical casts in orthopedics
• a filler in paint
• in toothpaste
• casting metals molds
• agricultural soil additive, amendment, conditioner and fertilizer
• making tofu with curdled soybean milk
  

Domestic Production and Use:
In 2002, domestic production of crude gypsum was estimated at 16.1 million tons with an estimated valued of $117 million. The top producing States were, in descending order, Oklahoma, Iowa, Nevada, Texas, California, and Arkansas, which together accounted for 66% of total output. Overall, 27 companies produced gypsum at 51 mines in 19 States, and 10 companies calcined gypsum at 66 plants in 29 States. Almost 90 percent of domestic consumption, which totaled approximately 31.8 million tons, was accounted for by manufacturers of wallboard and plaster products.

Approximately 2.69 million tons for cement production, 0.84 million tons for agricultural applications, and small amounts of high-purity gypsum for a wide range of industrial processes, such as smelting and glassmaking, accounted for the remaining uses. At the beginning of 2002, capacity of operating wallboard plants in the United States was 36.8 billion square feet per year.

(Data in thousand metric tons, unless otherwise noted)