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The Gemstone Turquoise

Turquoise

Turquoise is an ancient gemstone, and has been highly regarded in many of the world's civilizations. Among the ancient empires it is best known among the Persian and Native American civilizations, where it was the most popular ornamental gemstone. Turquoise today remains a popular gemstone, and is one of the most important opaque gemstones. It is highly regarded due to its unique turquoise-blue color, and is the only gemstone to have an exclusive color named after it.

Color

? Blue, Green, Multicolored

Hardness

? 5 - 6

Chemical Formula

? CuAl6(PO4)4(OH)8 • 4H2O

Mineral Class

? Turquoise

Additional Properties

Crystal System
? Triclinic
Refractive Index
? 1.61 - 1.65
Double Refraction
? .04
Transparency
? Opaque
SG
? 2.6 - 2.8
Luster
? Waxy
Cleavage ? None

All About

The word Turquoise dates back to the 17th century, when trading routes brought Turquoise from Persia through the Middle East towards Europe. The traders passed through Turkey, known as "Turquie" in French, and the locals named the material "Turquies" ("Turkish") in reference to its coming from Turkey.

Turquoise can come in different shades of blue or green, and is commonly veined or mottled with brown or black oxides or a sandstone base. Some prefer this color veining, while others prefer a solid-colored stone. The best color in Turquoise is a solid, deep turquoise-blue hue. Greenish colors are less desirable and are not usually used as gemstones. Turquoise may occasionally also be mixed together with green Malachite or Chrysocolla, causing blue and green mottled gemstones.

Turquoise is a porous gemstone and is thus easily dyed. The dying is done to enhance the blue from more greenish or mottled stones.  Dyed stones can eventually wear off their enhanced colors over the years, or when exposed to certain chemicals or solutions. The luster of Turquoise is often dull, and it is therefore very common for certain dealers to impregnate or coat the Turquoise with a a plastic lubricant or wax to enhance its luster.  Due to the common practice of dying and enhancing Turquoise, this gemstone especially should only be purchased from reputable dealers who fully disclose all information.

The porous nature of Turquoise makes it more easily affected by oils and cleaners. Because of this, Turquoise gemstones should not be washed with anything other than water. Turquoise is also a relatively soft gemstone, and extra care should be exercised to prevent it from scratching.

Uses

? Turquoise is among the most popular bead gemstones, and Turquoise bead bracelets and necklaces are also extensively used. Tumbled rough Turquoise gemstones may also be stranded into rings and necklaces. Turquoise is frequently cut and polished into cabochons, and can be used as large pendant stones and in rings. Ornate carvings are occasionally carved from Turquoise, and cameos and scarabs are also used. Turquoise remains an extremely important gemstone among Native Americans, and is by far the most popular gemstone in that culture. It is used in all forms of tribal jewelry, often associated with Silver.

Varieties

?

False Names

? Bone Turquoise, Fossil Turquoise, Occidental Turquoise, and Turquoise Odontolite are all synonyms of Odontolite.

Treatments & Enhancements

? Turquoise is frequently lubricated with oils or waxes to enhance its color and luster, and sometimes also to increase its durability. Another practice often applied to Turquoise is dyeing. Lighter colored stones as well as greenish hued Turquoise can easily be dyed a deeper blue color due to its porous and absorbent nature. Other materials, especially white Howlite and Chalcedony are occasionally dyed blue as an artificial simulant of Turquoise.

Turquoise Sources

? Traditional sources included Iran, Israel, Egypt, and the American Southwest. Today, Turquoise is mined chiefly in Iran, Afghanistan, China, Australia, Chile, Mexico, and in the U.S. states of Arizona and Nevada.

Similar Gemstones

? Lapis Lazuli is a deep blue color, and Variscite and Amazonite are greener as well as softer. Chrysocolla is softer, and Smithsonite and Hemimorphite are rarely used as gemstones.

Turquoise in the Rough Photos

?


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