1911 Encyclopædia Britannica/Almandine
|←Almanac||1911 Encyclopædia Britannica, Volume 1
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ALMANDINE, or Almandite, a name applied to certain kinds of precious garnet, being apparently a corruption of alabandicus, which is the name applied by Pliny to a stone found or worked at Alabanda, a town in Caria in Asia Minor. Almandine is an iron alumina garnet, of deep red colour inclining to purple. It is frequently cut with a convex face, or en cabochon, and is then known as carbuncle. Viewed through the spectroscope in a strong light, it generally shows three characteristic absorption bands, as first pointed out by Prof. A. H. Church.
Almandine occurs rather abundantly in the gem-gravels of Ceylon, whence it has sometimes been called Ceylon-ruby. When the colour inclines to a violet tint, the stone is often called Syrian garnet, a name said to be taken from Syriam, an ancient town of Pegu. Large deposits of fine almandine-garnets were found, some years ago, in the Northern Territory of South Australia, and were at first taken for rubies, whence they were known in trade for some time afterwards as Australian rubies.
Almandine is widely distributed. Fine rhombic dodecahedra occur in the schistose rocks of the Zillerthal, in Tyrol, and are sometimes cut and polished. An almandine in which the ferrous oxide is replaced partly by magnesia is found at Luisenfeld in German East Africa. In the United States there are many localities which yield almandine. Dr G. F. Kunz has figured a crystal of coarse almandine weighing 9⅔ lb. from New York city. Fine crystals of almandine embedded in mica-schist occur near Fort Wrangell in Alaska. The coarse varieties of almandine are often crushed for use as an abrasive agent. (See Garnet.)