1911 Encyclopædia Britannica/Rubellite

From Wikisource
Jump to: navigation, search

RUBELLITE, a red variety of tourmaline (q.v.) used as a gem-stone. It generally occurs crystallized on the walls of cavities in coarse granitic rocks, where it is often associated with a pink lithia-mica (lepidolite). The most valued kinds are deep red; the colour being probably due to the presence of manganese. Some of the rubellite is found in Siberia, whence it is sometimes called siberite, or passes under the misleading name of "Siberian ruby." The mills at Ekaterinburg, where it is cut and polished, draw most of their supplies from the Ural Mountains—chiefly from Mursinka, Sarapulskaya and Shaitanka, near Ekaterinburg—but specimens are occasionally found at Nerchinsk in Transbaikalia. Burma is famous for rubellite, but little was known as to the conditions of its occurrence there until after the British annexation, when the old workings were visited and described by C. Barrington Brown and by F. Noetling. The pits which yield rubellite are dug in alluvial deposits in the Möng-long valley, some miles to the S.E. of Mogok, the centre of the ruby country. It was here that the Chinese obtained the rubellite so much valued in China for buttons of the caps of mandarins of certain rank. In the British Museum there is a remarkable specimen of crystallized rubellite of large size and fine form, but of poor colour, which was presented by the king of Ava to Colonel Michael Symes on the occasion of his mission in 1795. Very fine rubellite is found in the the United States, notably at Mount Mica, near Paris, Oxford Co., Maine, where the crystals are often red at one end and green at the other. Mount Rubellite, near Hebron, and Mount Apatite at Auburn, are other localities in the same state from which fine specimens are obtained. Chesterfield and Goshen, Mass., also yield red tourmaline, frequently associated with green in the same crystal. Pink tourmaline also occurs, with lepidolite and kunzite, in San Dieg Co., California. In Europe rubellite occurs sparingly at a few localities, as at San Piero in Elba and at Penig in Saxony, but the mineral is rarely if ever fit for the lapidary. (F. W. R.*)