Gypsum is a very soft mineral composed of Calcium Sulphate Dihydrate, with the chemical formula CaSO4·2H2O. It has colourless and transparent variety that shows a pearl like luster and has been described as having a moon like glow.
It may also occur silky and fibrous, and is called satin spar. Gypsum is one of the more common minerals in sedimentary environments. It is a major rock forming mineral that produces massive beds, usually from precipitation out of highly saline waters. The crystals can also be quite large. Gypsum is a natural insulator, feeling warm to the touch when compared to a more ordinary rock or quartz crystal. Plaster of Paris is made by heating gypsum to about 300 degrees Fahrenheit, driving 75% of the water out of the mineral. Hardness is 2 and can be scratched by a fingernail. Specific Gravity is approximately 2.3+ (light)
Uses
Drywall
Plaster ingredient.
Fertilizer and soil conditioner.
A Binder in Fast-Dry tennis court clay.
A Binder in Fast-Dry tennis court clay.
Plaster of Paris (surgical splints; casting moulds; modeling).
A soy bean curd coagulant, making it ultimately a major source of dietary calcium, especially in use of few dairy products.
Adding hardness to water used for homebrewing
Blackboard chalk.
A component of Portland cement used to prevent flash setting of concrete.
