Note 43 — Chapter V
Reading edition
Gypsum, or sulphate of lime, consists of sulphuric acid 46·31, lime 32·90, and water 20·79. The massive gypsum is called Alabaster; the transparent gypsum Selenite; powdered calcined gypsum forms Plaster of Paris. The fibrous gypsum has a silken lustre, and is used for ear-rings, brooches, and other ornaments. Fibrous gypsum of great beauty occurs in Derbyshire; veins and masses of this substance abound in the red marls bordering the valley of the Trent.