Although commonly quite small in size, pyrope has occasionally attained to considerable size. According to De Boodt the Kaiser Rudolph II had one in his possession valued at 45,000 thalers (about £6750). The Imperial Treasury at Vienna contains a stone as large as a hen’s egg. Another about the size of a pigeon’s egg is in the famous Green Vaults at Dresden, and the King of Saxony has one, weighing 468½ carats, set in an Order of the Golden Fleece. (_c_) RHODOLITE This charming pale-violet variety was found at Cowee Creek and at Mason’s Branch, Macon County, North Carolina, U.S.A., but in too limited amount to assume the position in jewellery it might otherwise have expected. In composition it lies between pyrope and almandine, and may be supposed to contain a proportion of two molecules of the former to one of the latter. Its specific gravity is 3·84, refractive index 1·760, and hardness 7¼. It exhibits in the spectroscope the absorption-bands characteristic of almandine. (_d_) ALMANDINE (_Carbuncle_) This variety is iron-aluminium garnet corresponding to the formula Fe_{3}Al_{2}(SiO_{4})_{3}, but the composition is very variable. In colour it is deep crimson and violet or columbine-red (Plate XXIX, Fig. 8), but with increasing percentage amount of ferric oxide it becomes brown and black, and opaque, and quite unsuitable for jewellery. The name of the variety is a corruption of Alabanda in Asia Minor, where in Pliny’s time the best red stones were cut. Almandine is sometimes known as Syriam, or incorrectly Syrian garnet, because at Syriam, once the capital of the ancient kingdom of Pegu, which now forms part of Lower Burma, such stones were cut and sold. Crimson stones, cut in the familiar _en cabochon_ form and known as carbuncles, were extensively employed for enriching metalwork, and a half-century or so ago were very popular for ornamental wear, but their day has long since gone. Such glowing stones are aptly described by their name, which is derived from the Latin _carbunculus_, a little spark. In Pliny’s time, however, the term was used indiscriminately for all red stones. It has already been remarked that the word spinel has a similar significance. The specific gravity varies from 3·90 for transparent stones to 4·20 for the densest black stones, and the refractive index may be as high as 1·810. Almandine is one of the hardest of the garnets, and is represented by the symbol 7½ on Mohs’s scale. The most interesting and curious feature of almandine lies in the remarkable and characteristic absorption-spectrum revealed when the transmitted light is examined with a spectroscope (p. 61). The phenomenon is displayed most vividly by the violet stones, and is, indeed, the cause of their peculiar colour.