gypsum
noun
- mineral, calcium sulfate with bounded water
Wiktionary
Pronunciation: /ˈd͡ʒɪp.səm/
noun
Etymology: From Latin gypsum, from Ancient Greek γύψος (gúpsos). Doublet of gesso.
- A mineral consisting of hydrated calcium sulphate. When calcinated, it forms plaster of Paris.
“...but he has been able to analyze the matter removed, and to prove it, by chemical evidence, to consist of Prussian blue, and gypsum principally.”
“Besides being abundant, gypsum is easily refined into a powder for plaster or formed into sheets of wallboard.”