What is gypsum?

   Gypsum is a mineral composed of lime, sulphur, and water. Like marl, it is used as a fertilizer. Gardeners buy it in sacks under the name of land plaster. It is used also in the manufacture of glass and porcelain. When heated to drive off moisture gypsum falls into a powder which has the quality of hardening or setting quickly if moistened again. The most noted gypsum quarries in the world are near Paris, whence the name, plaster of Paris. Plaster of Paris ground fine is much used in the arts. Paperhangers mend walls with it. Plasterers use it in the finer sorts of work. Mixed with glue it is used for stucco work in the execution of cornices, flowers, garlands, festoons, fruits, scrolls, and other ornamental designs. Extensive beds are worked in various countries of Europe, especially England and France. In America, Nova Scotia, New York Michigan, Kansas, and Iowa produce considerable quantities. Gypsum is produced also in Virginia, South Dakota, California, Utah, and Wyoming.