gypsum

American  

[jip-suhm] / ˈdʒɪp səm /

noun

gypsums plural

1. a very common mineral, hydrated calcium sulfate, CaSO 4 ⋅2H 2 O, occurring in crystals and in masses, soft enough to be scratched by the fingernail: used to make plaster of Paris, as an ornamental material, as a fertilizer, etc.

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gypsum British  

/ ˈdʒɪpsəm, dʒɪpˈsɪfərəs, ˈdʒɪpsɪəs /

noun

1. a colourless or white mineral sometimes tinted by impurities, found in beds as an evaporite. It is used in the manufacture of plaster of Paris, cement, paint, school chalk, glass, and fertilizer. Composition: hydrated calcium sulphate. Formula: CaSO 4 .2H 2 O. Crystal structure: monoclinic

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gypsum Scientific  

/ jĭp′səm /

1. A colorless, white, or pinkish mineral. Gypsum occurs as individual blade-shaped crystals or as massive beds in sedimentary rocks, especially those formed through the evaporation of saline-rich water. It is used in manufacturing plasterboard, cement, and fertilizers. Chemical formula: CaSO ₄ ·2H ₂ O.

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Other Word Forms

Derived Forms

• gypseous
  adjective
• gypsiferous
  adjective

Inflected Forms

Nouns

• gypsums
  plural

Etymology

Origin of gypsum

1640–50; < Latin: chalk < Greek gýpsos chalk, gypsum

Explanation

Gypsum is a mineral — specifically, hydrated calcium sulfate — used in making many types of cement and plaster, especially plaster of Paris. It’s also in cement, tofu, and beer. Yum? Gypsum is everywhere! If you're studying chemistry or just want to build something, you may encounter gypsum, which is a white, chalky (or sometimes colorless) mineral used to make plaster of Paris and other building materials such as cement. Plaster of Paris is named from the massive gypsum deposits of Montmartre in Paris. But you won’t just find gypsum in art class. Besides its use in building materials, gypsum is used in making fertilizer and tofu.

Example Sentences

See Examples For:

gypsum gypsums

Lynas however, says its by-product from rare earth refining produces a non-toxic, non-radioactive magnesium-rich gypsum and an iron phosphate with a very low level of naturally occurring radioactive material.

From Barron's ● Apr. 22, 2026

For the rest of the building is disappointingly lackluster—boxy white galleries and corridors in “painted gypsum board,” i.e., sheetrock.

From The Wall Street Journal ● Dec. 17, 2025

Additionally, the basin was filled with layers of salt and gypsum.

From Science Daily ● Oct. 8, 2025

The best remedy for high pH, Wallace said, is to add gypsum to your soil and avoid things that can make the soil more alkaline, such as crushed concrete.

From Los Angeles Times ● Apr. 24, 2025

When he came home, he’d be covered with white gypsum powder, and sometimes we’d play ghost and he’d chase us.

From "The Glass Castle" by Jeannette Walls

To class it according to the type of European formations I would range it among the gypsums, often muriatiferous, that cover the Alpine limestone or zechstein.

From Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 3 by Humboldt, Alexander von

Related Words

• adhesive
• cement
• glue
• lime
• mortar
• stucco