The Gemstone 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
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Blue, Green, Multicolored
Chemical Formula
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CuAl
6(PO
4)
4(OH)
8 • 4H
2O
Mineral Class
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Turquoise
Additional Properties
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Refractive Index
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1.61 - 1.65 |
Double Refraction
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.04 |
Transparency
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Opaque |
SG
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2.6 - 2.8 |
Luster
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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
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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.
False Names
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Bone Turquoise,
Fossil Turquoise,
Occidental Turquoise, and
Turquoise Odontolite are all synonyms of
Odontolite.
Treatments & Enhancements
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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
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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
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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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