Aquamarine Buying Guide: All you need to know
Besides the dark green beryl, which we know as emerald, and the blue beryl, which is the Aquamarine, we have other colors in this mineral species (a silicate of beryllium and aluminum) and these are called beryls only, according to their colors. The mineralogist regards the whole class simply as beryl, but as we are concerned with jewel stones, we must make some distinction when describing what is more properly gem material and it has all the same physical properties such as specific gravity, hardness, and refractive indices as its rarer companion.
The fact that aquamarine is found more abundantly and often in large and flawless crystals makes it a much less costly stone than emerald. Pale stones are comparatively cheap, especially those which approach being colorless, but good blue stones, which are very beautiful, are fairly rare and obtain high prices.
Aquamarine is the name applied to the bluish beryls. In other words, it is exactly the same stone as an emerald, except for color, not an ordinary rock. We, therefore, have yellow beryls, sometimes known as golden beryl and heliodor; the rose pink, called pink beryl or morganite (after J. Pierpont Morgan of New York who presented a large collection now on display at The American Museum of Natural History in New York); white beryl, also called gosheniteNor does it contain the flaws and "silk" so often seen in sapphires. Its color is entirely different from that of the sapphire, being more of a limpid, deep sea blue, and the two varieties cannot be confused by anyone accustomed to Pink beryl is a beautiful, true rose pink, and it is the largest pink transparent stone found. It is very pure and clear, with less of a magenta tint than tourmaline and without the lilac color seen in kunzite. Aquamarine, which does not change in artificial light, is not cloudy or heavy looking like most blue zircons.
But all these crystallize in hexagonal columnar crystals. Cleavage is indistinct, and dichroism is weak, except in the deeper bluish and greenish stones, when twin colors are distinctly seen. Hardness is almost universally 7 3/4, specific gravity about 2.74, and refractive indices 1.57-1.58. Aquamarine is the lightest of the beryls, many stones giving a reading as low as 2.69; the pink beryl, on the other hand, sometimes reaches 2.80. The various colors are due to traces of impurities.; green beryl, and other transparent varieties whose colors may be intermediate or indefinite, and which are consequently known simply as beryls. There are dull, cloudy stones, some even opaque, and these are not cut for use in jewelry. handling stones. Blue topaz is perhaps its nearest equivalent in color, for when both are cut and polished, they may both be pale with a high polish. But the higher specific gravity would be sufficient to distinguish it from aquamarine.
The shades in aquamarine have been ascribed to alkaline earths, influenced by ferric or chromic oxides. The color is almost always homogeneous throughout the material, and it has the advantage of appearing the same by both natural and artificial lights, a quality which is not present in all sapphires and zircons. Some aquamarines may be enriched in color by heating, but many specimens remain unaffected. It is interesting to note that some stones of a fairly good color recently mined in Brazil have been noticed to fade appreciably on exposure to the light. As this peculiarity was traced to one mine, no further stones were offered for sale and the mine was closed.
Crystals of varying sizes occur in geodes and granite rocks. The U.S.S.R. (Siberia and the Ural Mountains), Brazil (Bahia, MinasGeraes, Rio de Janiero), the U.S.A., and Madagascar supply most of the gem material. From Madagascar come the finest pink beryls and aquamarines. They are found in the valley of the Sahatony, a tributary of the River, which flows along the west slope of Mount Bity. Other beryls are also found in this locality, and they occur in veins of pegmatite which penetrate the alternating layers of mica schist and quartzite. These veins are often nearly 100 feet in thickness, and they also contain deposits of amazonite, kunzite, and tourmaline. It may be noted that pink beryls, when exposed to X-rays, assume a vivid cerise color, and brilliance is increasedManandorapurposes are usually clear of serious blemishes. When cut, all the usual forms are used, step, brilliant, mixed, marquise, and briolettes being common. The larger pieces, which are often mounted as centerpieces of pendants, are generally step cut, and when mounted with diamonds in platinum or palladium, fine effects are obtained..
Stones Cut for Jewelry Faults usually take the form of cavities or striae, but
Blue, white, pink, and yellow stones are mined in the states of Colorado and California in the U.S.A., and aquamarines come from southern Siberia, where they occur in cavities of a quartz-topaz rock. MinasGeraes in Brazil, which furnishes so many gems, including diamonds, also gives us aquamarines. It was here that one of the largest and finest specimens known was mined in the year 1910. Found at a depth of only 15 feet, the crystal measured 19 inches by 16 inches and weighed 243 lbs. It was so transparent that it could be seen from one end to the other. It was sold for over $ 14,000 (£5,000). Aquamarines and other beryls are found in New South Wales, Australia and in Ontario, Canada, but stones from these sources have little commercial value.
Crystals are often so large that they may be carved into a variety of objects. In former days, they were sometimes used as handles for daggers, while the Ancients found the stone sufficiently soft to carve and engrave. Ancient engraved specimens, as well as cameos, have been found, and pale aquamarines were also used at one time as spectacle lenses.
Many fine specimens are in existence, and one stone of fine quality, weighing 875 carats, may be seen in the Mineral Gallery of the British Museum. Another, said to be the largest specimen in the world, was shown by the Brazilian Government in New York during November 1946. Weighing 56 lbs., or about 25,000 carats, this crystal is hexagonal in shape, 11 inches high, and 10 inches in diameter.
As the gemstone, aquamarine is subject to fluctuating demands caused by fashion, and its value therefore varies. But deep blue stones always realize a good price since they are comparatively rare, and there is a strong demand for them in the U.S.A., South America, and in England. Cheaper qualities are popular on the European continent, and these are sold in moderately priced pieces of jewelry. Pale blue synthetic stones are quite often sold as synthetic aquamarines, but they are either synthetic sapphires or synthetic spinels.
The mineral beryl is the chief source of beryllium, and this, if found in commercial quantities, would be of considerable use in industry on account of its remarkable properties, such as comparative lightness, strength, resistance to heat and corrosion. Beryl contains about five percent of beryllium, a valuable mineral. The common variety, often found in many granite rocks, is produced largely as a by-product in the mining of feldspar and mica.
