Encyclopædia Britannica, Ninth Edition/Alabaster

ALABASTER (said to be derived from the Arabic al batstraton, the whitish stone), a name properly restricted to the fine massive variety of gypsum, or sulphate of lime, which is used in the manufacture of ornamental vases, statuettes, clock-frames, &c. When pure, it is of a brilliant pearly-white lustre, so very soft as to be easily scratched by the nail, and is soluble to a slight extent in water. It occurs in large and very pure masses at several localities in Tuscany, and is turned or chiselled into its various ornamental forms in Florence, which is the centre of the alabaster trade. At a time when the taste for alabaster work was more general than now, it was quarried at Lagny, near Paris. In England considerable deposits are found in various localities, but chiefly in Derbyshire and Staffordshire, where it is worked to form the plaster of Paris moulds used by potters; hence it is termed "potters' stone." Fine blocks found in quarrying the potters' stone are reserved for the alabaster turners. A yellow variety of alabaster, found at Sienna, is termed "alabastra agatato." When it presents a fibrous structure, it is known as "satin spar," which when cut has the opalescent appearance of "cat's eyes." Oriental alabaster is the name applied to the stalagmitic variety of carbonate of lime formed on the floors of limestone caves by the percolation of water, an entirely different material from the above. It is usually clouded or banded in an agate-like manner, and hence is sometimes known as onyx marble. The alabaster yielded by celebrated quarries, known to the ancients and now again worked, in the province of Oran, Algeria, is of this kind. It is this oriental alabaster that is referred to in the Bible, the άλαβαστρίτης of the Greeks. The stone was held in very high estimation among the civilised nations of antiquity, being then chiefly procured from quarries in the neighbourhood of Thebes, which to this day remain unexhausted. At the present time it is procured from Oran (Algerian onyx), the Pyrenees, Chili, California, &c. In the Soanean Museum there is an Egyptian sarcophagus in oriental alabaster, covered with hieroglyphics, which was purchased by Sir John Soane for 2000 guineas.