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December Birthstone Turquoise
History of Turquoise
Turquoise, the blue cousin to lapis lazuli, has been valued for thousands of years. Turquoise may have been the first gemrock used in jewelry. It was believed by the ancient Egyptians the stone had mystical powers and used it in art, figures, decorations and ornaments such as Queen Zar's jewelry (5500 BC). Turquoise became a major trade and important barter item for the early Persians. The sky-blue gemstones were worn round the wrist or neck in the ancient Persian kingdom as protection against unnatural death. Persian turquoise was found in ancient graves in Turkistan, and in graves throughout Caucausus in the 1st to 3rd century A.D. In Japan, turquoise was unknown until the 18th century.
Turquoise can be found anywhere in the world, but high-grade turquoise is mostly found in Persia, China, Tibet and the Southwest. The early mines in Egypt, Sinai, were already worked out in 2000 B.C. The stone was also used to make artifacts, ornaments and to decorate palaces and temples. Turquoise was first sent from Turkey to Europe, hence its name, which means "Turkish" in French.
What is Turquoise and Where to Find Turquoise
Turquoise stone is a hydrous basic phospate of copper and alumunium which is formed as waterr trickles through a host stone for about 25-30 million years, gradually leaving a deposit. The hardness of the stone usually varies from 5-6 according to Mohs scale of hardness. Turquoise found nearest the surface of the earth usually are the hardest turquoise, where it’s had a chance to dry or cure. Softer turqouise is chalk-like, too porous and soft to be used unless it’s treated. Chemicals are used to change or enhance the color of turquoise.
Turquoise can be formed as nuggets and vein turquoise. When it is deposited in open cracks and voids in rocks, then vein turquoise is formed. Most of the clear turquoise found does originally form as veins. Sometimes turquoise will form surounding and mixed in with angular fragments of broken country rock. It is then called as turquoise breccia. It can be also formed in a cavity lined with crystals of quartz, it can even take the place of another crystal when that crystal disolves and become a "pseudomorph".
Pieces of fine turquoise are backed with an epoxy cement mixture when they are too thin to be cut alone, this is to strengthen the stone and make it much less likely to break and easier to cut. Without backing, those small turquoise nuggets and tiny vein pieces would not be usable. Because of their porosity they easily absorb grease and dirt and change in color to an unattractive green. Exposure to sunlight or heat is also injurious to the color of the turquoise. To avoid scratching your turquoise jewelry, handle it carefully and dont store it with other harder gemstones that might rub against it and cause damage. Clean your turquoise with warm, sudsy water and dry it with a soft cloth immediately. Avoid commercial jewelry cleansers.
Different Colors of Turquoise
The Color of Turquoise can vary greatly even within the same mine. If the mix has more alumunium, the turquoise will be colored in the green to white range; if more copper, in the blue range. The addition of zinc will produce a yellow-green color and harden the stone even more. Sky-blue is the most popular color, though green color is the rarest. Turquoise can also come in varying grades, the higher-quality usually has very little porosity and is harder and will not change color by absorbing grease and oil. Other colors that appear in the stone can come from the host stone that the turqouise formed in, and are called "matrix." Matrix color varies because turquoise forms in different types of rock. The host rock can be black, rust-colored, brown or be darker shades of blue or green. A black matrix is usually from iron pyrite; a yellow to brown matrix from rhyolite, and a gold-brown matrix from iron oxide. When stones are cut, some of the matrix remain bound to the turquoise. Stones with thin lines of matrix distributed throughout them is called spider web turquoise.
Turquoise Beads, Statue and Art
Turquoise in China and Tibet
Turquoise was used in very early times in China and much has always been worn in jewelry. To the Chinese, turquoise is second only to jade. Tibet also has its own source of turquoise, which is usually contain significant amount of spider webbing. In Tibetan culture, turquoise is an essential and highly valued stone. Turquoise was used for currency in certain areas of Tibet. They have preferred turquoise to any other gemstone and virtualy every Tibetian possess some turquoise. It is worn by women and men alike in a variety of accessories and jewelry, as well as being set into statues and other ritual and religious objects. The Mongols’ knowledge of turquoise likely came from China and Tibet. It became immensely popular. Turquoise is considered beneficial to general physical well-being, the cooling nature of the stone is thought to help high blood pressure, purify the blood and benefit the liver.