Gypsum

(Gr. γύψος ). The property of rapid consolidation renders gypsum very available for taking casts of works of art, . It is much employed in architectural ornaments. The gypsum of Paris is called Montmartrite, and forms the best Plaster of Paris, as it resists the weather better than purer sorts. It contains 17 per cent. of carbonate of lime. (See also Alabaster.)