gypsum

[jip-suhm]

noun

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.

gypsum

/ 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

gypsum

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.

Other Word Forms

• gypsiferous adjective
• gypseous adjective

Word History and Origins

Origin of gypsum¹

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

Word History and Origins

Origin of gypsum¹

C17: from Latin, from Greek gupsos chalk, plaster, cement, of Semitic origin

Related Words

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