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Garnet Stone
 Garnet has been extremely popular as a red gemstone from remote antiquity, perhaps largely because the red varieties are not particularly rare. Most of the stones are called 'carbuncle' by the ancients - and by more recent sources also - must have been garnets, though the name was used somewhat indiscriminately for various red stones. What is not generally realized is that garnet can in fact occur in most colors except blue, including a magnificent green, and also in black and colorless forms. This wide variety of coloration occurs because garnet forms an isomorphous series. Each garnet usually contains at least traces of one or more of other members of the family; some of the varieties are attractive in themselves and their combination produces still further interesting forms.  All garnets are silicates of two metals. They crystallize in the cubic system, usually as modified dodecahedra, and can be fully transparent to opaque. The name 'garnet' derives from the Latin granatum, pomegranate, presumably by reference to the color, but the root of the name goes back to Sanskrit. Six varieties of garnet are distinguished in accordance with their chemical composition and five of them are used as gemstones. They are called pyrope, almandine, spessartine, grossular, andadite and uvarovite. The latter is very rare and hardly ever occurs in forms which can be cut.Pyrope, from Greek pyropos , fire like, displays the brightest red among garnets when pure. This is, however, rarely the case for for most pyropes contain an admixture of almandine molecules which darken them. Pyrope is one of the first minerals to crystallize out at a high temperature from a magma containing it and has been found in some very ancient igneous rocks. Good specimens have also come from kimberlite pipes, which carry diamonds, and minute pyropes even occur as inclusions within them. There are many localities where pyrope is found - Australia, various parts of Africa and South America, and Arizona and Colorado in the USA - but by far the most prolific source of small stones was in Bohemia. Garnets from that country had a tremendous vogue in the last century. Small rose-cut stones were set in gold clusters to form every kind of jewelry. Almandine has an even wide distribution, but fine stones are not very common. It is the traditional garnet of India, a darkish crimson in color and widely used in oriental jewelry. It usually contains some pyrope. It is valued somewhat more highly than pyrope and found in rather larger stones. It's often cut into cabochons, to which the name 'carbuncle' is still sometimes applied and it occasionally displays a weak four-rayer star. The darker stones are not attractive, and in order to lighten the color cobochons are sometimes hollowed out at the back and foiled to reflect more light. Spessartine is a rather rare manganese garnet that occurs in a number of attractive colors, from yellow and orange to brownish-red. Having a high retractive index and density it forms lustrous stones. The name spessartine comes from a district in Germany where the stone was found but more recent sources are in the gravels of Ceylon and Minas Gerais, Brazil; in a lode of Broken Hill, Australia; and in Virginia and Nevada in the USA. The three other garnet varietie also tend to occur mixed with each other in isomorphous forms and are therefore collectively known as the 'ugrandite' garnets. The most common of them is grossular garnet, so named after grossularia, the Latin name for gooseberries, which the green translucent, cryprto-crystalline variety resembles in color. This comes mainly from Transvaal, South Africa, and used chiefly for ornamental carvings. Grossular of gem quality is yellow, orange or brownish in color and known as hessonite garnet. It is transparent though numerous inclusions often give it a treacly appearance. It is also known as 'cinnamon stone' and as 'jacinth', but the latter appellation is to be deprecated since it has also been applied to brown zircon. The main source of hessonite is in the gem gravels of Ceylon where it occurs together with zircon. There is also a pink translucent variety which is found at Xalostoc, Mexico. Grossular may be regarded as the most versatile- although by no means the most valuable and beautiful of garnets. Andradite or it's green form demantoid, which is colored by chromium to aim intense green in the best stones, in addition to which it possesses rather higher color-dispersion or fire than diamond and a high refractive index; a truly splendid stone. Unfortunately, it rarely found in large crystals, so that gems cut from it very seldom reach 3 carats in size. Tiny demantoids blend well with other gemstones and are sometimes used surrounding them. The fines specimens come from the Ural mountains (Russia), but green and yellow andradites also come from northern Italy and Switzerland. The name 'demantoid' refers to the diamond like sparkle of the stone. The last of the garnets, uvarovite - named after Count Uvarov, distinguished Russian academician - is always in intense chromium green in color but hardly ever occurs in sizes which can be cut. The few small stones cut for collectors tend to be rather cloudy. 
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