Turquoise, the blue cousin to lapis lazuli, has been known and valued for thousands of years. The early mines in Sinai, Egypt, were already worked out in 2000 B.C. Today the best quality Turquoise is found in Iran. Turquoise was first sent to Europe through Turkey, hence its name, which means "Turkish" in French.
The brilliant sky-blue color has made Turquoise a classic gemstone, especially when set in silver. Cut en cabochon Turquoise stones are used for all kinds of jewelry: brooches, necklaces, bracelets, rings and earrings. Due to its relative softness, 5-6 (Mohs scale) it can be carved into ornamental objects but requires some care. Light, perspiration, oil, cosmetics and household chemicals can all affect the color of Turquoise.
Turquoise has long been appreciated as a holy stone, a good-luck-charm or a talisman. It is believed to promote good fortune, happiness, and long life.
Turquoise is a birthstone for those born in December.
Where is Turquoise found?
Common Turquoise treatments
Turquoise legends & lore
Turquoise comes in sky-blue, blue-green and apple-green. Sky-blue is the most popular color, though green is the rarest. Pure blue colored Turquoise is rare. The gems are mostly mixed together with brown, dark gray, or black veins of other minerals or of the hosting rock (like chalcedony or opal, brown limonite, black chert, or white kaolinite). Those stones are called Turquoise matrix. Color ranges through shades of blue to blue-green, to yellowish green depending on the amount of copper (reponsible for blue) chromium or vanadium (reponsible for green,), and iron (reponsible for yellow). There are rare specimens of blue-violet color, which contain strontium impurities.
In general the color is only stable if the stone is not exposed to strong light, high temperatures, perspiration, oil, cosmetics and household chemicals. A loss of its natural water content (18-20%) results in undesirable color-changes as well. The most desired sky-blue color changes at 250 degrees C (482 degrees F) into a dull green. Most of the Turquoise found in the United States contains Fe, substituting Al, which causes a greenish color.
Turquoise is an affordable stone for its carat weight. It's fairly soft, 5-6 on the Mohs scale, and requires some care. A Turquoise ring should always be removed before hands are washed.
A spotless sky-blue is the most desired color of turquoise, but rarely found. Apple green turquoise is rare.
Turquoise is translucent to opaque with a waxy luster. There is only one known deposit, in the state of Virginia, where turquoise is found in transparent to translucent visible crystals. Those specimens are rare and expensive.
Classically turquoise is cut en cabochon for brooches, necklaces, bracelets, rings and earrings, or carved into ornamental objects.
Turquoise location and deposits
The finest qualities are found in Iran (near Nishapur). Other deposits are in Afghanistan, Argentina, Australia, Brazil, China, Israel, Mexico, Tanzania and the United States.
Common Turquoise treatments
Turquoise is porous and therefore often soaked with artificial resin that improves color and hardens the surface. Color-improvements can be gained with oil or paraffin, or other color agents like Berliner blue, aniline colors, or copper salt.
Turquoise has enjoyed popularity and fame since the Pharaohs ruled ancient Egypt. In the early Victorian period, sky-blue turquoise was most popular in Europe and has never lost its appeal. In the Middle East it is traditional to set turquoise in gold, sometimes with diamonds. Today silver settings are popular, especially in the United States, where the "Indian Jewelry" is a perennial fashion trend.
Color: Sky-blue, blue-green, apple-green
Chemical composition: CuAl6(PO4)4(OH)8 – 4H2O; a copper containing basic aluminum phosphate
Crystal system: Seldom triclinic, grape-shaped aggregates
Hardness: 5-6 (Mohs scale)
Specific gravity: 2.31 – 2.84
Refractive index: 1.610 – 1.650
Color of streak: White,
Absorption spectrum: (460), 432, (422)
Fluorescence: Weak; green-yellow, light blue
The Turquoise zodiac, myth & legend
Turquoise has long been appreciated as a holy stone, a good-luck-charm or a talisman found in every type of jewelry. It is believed to promote good fortune, happiness, and long life.
Turquoise is a birthstone for those who are born in December.
In Antiquity, as well as in the Middle Ages, people believed that the cosmos is reflected in gemstones. Turquoise is assigned to the planets Saturn, Uranus and Venus. The esoteric movement revived the ancient belief and the gem industry made it another marketing tool to promote certain gems.
The healing powers of gems remain a controversial issue, but are mentioned for centuries by healers, shamans and medicine men. Whether it’s a fact or a placebo effect doesn’t matter, if it helps. The safest approach is to wear the gemstone in skin contact to the troubled part of the body. Turquoise is said to be of help for heart ailments, sciatica, toenails problems and blisters.