What does gypsum mean?
Gypsum is a soft mineral made of hydrated calcium sulfate, a compound that occurs naturally in sedimentary rock and can be heated to produce plaster. Its most familiar modern uses are in plaster, wallboard, and ceiling panels, where its fire resistance and ease of working are valuable. Builders and conservation specialists also use gypsum as a molding material, while geologists may distinguish transparent, fibrous, or fine-grained varieties. The word carries a mainly technical and industrial tone, but it is not restricted to specialists: it is widely encountered in home improvement, art conservation, and building history. Its importance extends far beyond modern interiors, because gypsum plaster was used in ancient and historic architecture long before drywall became common. The mineral is also a familiar geological example of a hydrated salt. Understanding gypsum clarifies the close relationship between a naturally occurring mineral, a manufactured powder, and the finished materials used in construction.
nounA soft, white or colorless mineral consisting of hydrated calcium sulfate, especially one used after heating to make plaster and drywall. It occurs in sedimentary deposits and is also found in varieties such as selenite and alabaster.
- The soft mineral hydrated calcium sulfate, occurring in sedimentary deposits and used in construction and crafts.
- Plaster or a similar building material made chiefly from gypsum, especially calcined gypsum.
"The restorer used finely ground gypsum to repair a crack in the ceiling."
"Gypsum plaster was applied to the walls of the historic building."
"The geologist examined a clear gypsum crystal from the quarry."
Usually used as a mass noun, especially for the mineral or construction material; the plural is uncommon and may refer to separate quantities or objects.
"The samples included several pale gypsums from different deposits."
The mineral behind ancient plaster is also hiding inside many of today's drywall panels.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does gypsum come from?
The English word gypsum comes through Latin gypsum from the ancient Greek γύψος (gypsos), a term used for the mineral and for plastery material made from it. The Greek and Latin words refer to the substance's long-established use in building and sculpture. Modern English derivatives include gypsite, a variety or form of gypsum, and gypsiferous, meaning containing gypsum.
How gypsum is actually used
Gypsum is usually treated as a mass noun in technical and construction contexts. The term can sound specialized, but it is also familiar through its common use for plaster and wallboard.
Easily confused with gypsum
Gypsum names a mineral and building material, whereas gipsy is an old variant of Romani that is now widely regarded as offensive.