This article is about the mineral. For other uses, see Gypsum (disambiguation).
Gypsum
General
Category
Sulfate minerals
Formula (repeating unit)
CaSO4·2H2O
IMA symbol
Gp[1]
Strunz classification
7.CD.40
Crystal system
Monoclinic
Crystal class
Prismatic (2/m) H-M symbol: (2/m)
Space group
Monoclinic Space group: I2/a
Unit cell
a = 5.679(5), b = 15.202(14) c = 6.522(6) Å; β = 118.43°; Z = 4
Identification
Color
Colorless (in transmitted light) to white; often tinged other hues due to impurities; may be yellow, tan, blue, pink, dark brown, reddish brown or gray
Crystal habit
Massive, flat. Elongated and generally prismatic crystals
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.[4] It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk.[5][6][7][8] Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.
Fine-grained white or lightly tinted forms of gypsum known as alabaster have been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England.
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (2003). "Gypsum" (PDF). Handbook of Mineralogy. Vol. V (Borates, Carbonates, Sulfates). Chantilly, VA, US: Mineralogical Society of America. ISBN 978-0962209703. Archived (PDF) from the original on 6 February 2006.
^Gypsum. Mindat
^ abKlein, Cornelis; Hurlbut, Cornelius S. Jr. (1985), Manual of Mineralogy (20th ed.), John Wiley, pp. 352–353, ISBN 978-0-471-80580-9
^Institute, Canadian Conservation (14 September 2017). "Care of Objects Made of Plaster of Paris – Canadian Conservation Institute (CCI) Notes 12/2". www.canada.ca. Retrieved 20 January 2023.
^Make your own sidewalk chalk. (1998, July 21). Christian Science Monitor. 13.
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer...
than flat surfaces. The most common types of plaster mainly contain either gypsum, lime, or cement, but all work in a similar way. The plaster is manufactured...
board, gypsum board, buster board, turtles board, slap board, custard board, and gypsum panel) is a panel made of calcium sulfate dihydrate (gypsum), with...
(i) the fine-grained, massive type of gypsum, and (ii) the fine-grained, banded type of calcite. Chemically, gypsum is a hydrous sulfate of calcium, whereas...
National Gypsum Company is a company based in Charlotte, North Carolina, that produces drywall gypsum boards in the US. It has 17 gypsum board plants...
Gypsum block is a massive lightweight building material composed of solid gypsum, for building and erecting lightweight, fire-resistant, non-load bearing...
Gypsum recycling is the process of turning gypsum waste (from construction) into recycled gypsum, thereby generating a raw material that can replace virgin...
Gypsum concrete is a building material used as a floor underlayment used in wood-frame and concrete construction for fire ratings, sound reduction, radiant...
USG Corporation, also known as United States Gypsum Corporation, is an American company which manufactures construction materials, most notably drywall...
Gypsum Spring Formation is composed of massive white gypsum in the lower part, and alternating gypsum, red shale, dolomite and limestone. The Gypsum Spring...
dissolution of soluble carbonate rocks such as limestone, dolomite, and gypsum. It is characterized by features like poljes above and drainage systems...
The gypsum flora of Nova Scotia refers to a small group of plants that are restricted to naturally-occurring outcrops of gypsum. Nova Scotia is unique...
Datura stramonium, known by the common names thorn apple, jimsonweed (jimson weed), devil's snare, or devil's trumpet, is a poisonous flowering plant of...
Gypsum Recycling International A/S (GRI) is a recycling company based in Nærum, Rudersdal Municipality, Denmark. GRI offers a system for the recycling...
known as plaster of Paris, and another occurs naturally as the mineral gypsum. It has many uses in industry. All forms are white solids that are poorly...
been named Gypsum Queen, including: SS Gypsum Queen, a British merchant ships sunk during World War II whilst a member of Convoy SC 42 USS Gypsum Queen (SP-430)...
Gypsum Township may refer to: Gypsum Township, Saline County, Kansas Gypsum Township, Sedgwick County, Kansas This disambiguation page lists articles...
was purchased by Saint-Gobain of France. The company's subsidiary British Gypsum, which was the UK operating arm of the company, operates as a subsidiary...
family-owned company based in Iphofen, Germany, well known for drywall gypsum boards, founded in 1932. The company is a producer of building materials...
The resulting calcium sulfite oxidizes in air to give gypsum: CaSO3 + 1⁄2 O2 → CaSO4 The gypsum, if sufficiently pure, is marketable as a building material...
regions. The genus name is from the Greek gypsos ("gypsum") and philios ("loving"), a reference to the gypsum-rich substrates on which some species grow. Plants...