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Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon. [16] Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins.
The main sources of calcium sulfate are naturally occurring gypsum and anhydrite, which occur at many locations worldwide as evaporites. These may be extracted by open-cast quarrying or by deep mining. World production of natural gypsum is around 127 million tonnes per annum. [17]
Various sized cuts of 1 ⁄ 2 in (13 mm) drywall with tools for maintenance and installation . Drywall (also called plasterboard, dry lining, [1] wallboard, sheet rock, gib board, gypsum board, buster board, turtles board, slap board, custard board, gypsum panel and gyprock) is a panel made of calcium sulfate dihydrate (), with or without additives, typically extruded between thick sheets of ...
Selenitic lime, also known as Scotts' cement after Henry Young Darracott Scott, is a cement of grey chalk or similar lime, such as in the Lias Group, with about 5% added gypsum plaster (calcined gypsum). [13] Selenite is a type of gypsum, but selenitic cement may be made using any form of sulfate or sulfuric acid. [18]
A gypsum block is made of gypsum plaster and water. The manufacturing process [1] is automated at production plants where raw gypsum (CaSO 4 ·2H 2 O) is ground and dried, then heated to remove three-quarters of the bound water and thus transformed into calcium sulfate hemihydrate (CaSO 4 ·½H 2 O), also known as gypsum plaster, stucco, calcined gypsum or plaster of Paris.
Black alabaster is a rare anhydrite form of the gypsum-based mineral. The black form is found in only three veins in the world, one each in United States, Italy, and China. Alabaster Caverns State Park, near Freedom, Oklahoma, is home to a natural gypsum cave in which much of the gypsum is in the form of alabaster. There are several types of ...
Heating gypsum to make plaster of Paris; For cremation (at high temperature) Drying of tobacco leaves; Drying malted barley for brewing and other fermentations; Drying hops for brewing (known as a hop kiln or oast house) Drying corn (grain) before grinding or storage, sometimes called a corn kiln, corn drying kiln [8] Drying green lumber so it ...
Speleothems inside Optymistychna Cave. The entire cave lies under a 2 km square area in a layer of Neogene period gypsum that is less than 30 metres (98 ft) thick. [7] [9] The passages tend to be fairly small, no more than 3 metres (10 ft) wide and 1.5 metres (5 ft) tall for most, although at intersections they can be up to 10 metres (33 ft) tall. [7]