Turquoise: Properties, Facts and Photos

Turquoise is one of the oldest and most easily recognised minerals. It's also one of the most imitated, with fake material known to have been produced in ancient Egypt. Turquoise continues to be one of the most imitated gemstones.

Contents 1. What is Turquoise 2. Fake Turquoise 3. Colour of Turquoise 4. Article Pictures 5. Shop Turquoise

What is Turquoise?

Turquoise is a blue-to-green copper-bearing mineral that has been used as a gemstone for thousands of years.

Although turquoise can crystallise under exceptional conditions, well-formed crystals are extremely rare and usually very small. It more commonly occurs in massive form, meaning its crystals grow as one large, shapeless mass. 

Turquoise, which is a secondary mineral formed through the weathering of other minerals, is often found close to copper. It forms in veins, nodules, or crusts within a host rock.

It occurs in arid regions when rainwater carries copper and phosphate through the ground. As the water reacts with aluminium-bearing rocks, turquoise begins to form.

The name 'turquoise' comes from the word 'turquois,' meaning 'Turkish stone'. It was named by the French in the 17th century.

They believed it originated in Turkey when in fact it had only passed through there on its way to Europe. The stone would have been mined in northeastern Persia, modern-day Iran.

Despite being one of the oldest gemstones, turquoise is still extremely popular. Records from the reign of the Egyptian Pharaoh Semerkhet detail extensive mining operations involving thousands of workers.

Turquoise artefacts discovered in ancient Egyptian burial chambers have been dated to 3000 BC, while beads have been dated to 4000 BC. Stones found in Mesopotamia (present-day Iraq) date back to 5000 BC.

The most famous artefact is the funerary mask of King Tutankhamun. This priceless work of art features lapis lazuli, turquoise, white quartz, carnelian, amazonite, other gemstones and coloured glass.

Ancient Roman author and philosopher Pliny the Elder mentioned what is believed to be turquoise in his works Naturalis Historia. Published around 77 AD, he referred to it as 'callais' or 'callaina'.
In the Bible, turquoise is said to have been the first stone in the second row of the high priest breastplate. This religious garment was worn over the top of a type of tunic.

Turquoise has long been revered by Native American Indians, including the Navajo and Apache tribes. It's known to have been mined as early as 1000 AD by the Anasazi natives in the southwestern United States. It was also widely used by the Incas, Aztecs and Maya.

By far the most important gemstone used in traditional jewellery, many would argue that turquoise is fundamental to American Indian culture.

Napoleon I gave his second wife a diadem on the occasion of their marriage. Made by French jeweller Etienne Nitot et Fils of Paris, it originally featured emeralds and diamonds set in gold and silver.

In 1953, the diadem was sold to Van Cleef and Arpels, who, at some point between 1956 and 1962, replaced the emeralds with seventy-nine Persian turquoise cabochons. The emeralds, which were subsequently sold in other pieces of jewellery, were promoted as being from the historic diadem.

Fake Turquoise

Archaeologists have found fake turquoise in Egypt, which suggests it was likely to have been the first gemstone to be imitated.

Throughout history, it has been imitated more than any other natural stone. When buying turquoise, it's always worth considering whether it could be fake.

The most popular man-made materials used to produce fake turquoise are plastic, glass, and ceramic. If a stone is lightweight and warm to the touch, it's likely to be plastic. Other materials may not be quite as obvious.

White howlite is also widely used because it's relatively cheap, can have similar markings, and is porous, making it easy to dye. The spidery veins in howlite can easily be mistaken for the matrix in turquoise.

Trade names such as white turquoise or white buffalo turquoise are often used for dyed howlite. White turquoise does not exist.

Other minerals used to produce fake turquoise include low-grade chrysocolla or azurite and magnesite.

Fake turquoise can often be identified based on appearance alone. The most obvious clue is usually price, as genuine turquoise is rarely cheap.

The gemstones in the next photo come from a respected website that sells stock images. The photographer, whose collection is mostly diamonds, labelled them as "turquoise cabochons." They're synthetic, probably plastic.

The only thing vaguely turquoise about them is their colour. Not all fake turquoise is quite as bad as this. The double terminated point was being sold on a shopping platform. The supplier, based in China, stated that all of the crystals in their collection were genuine. 
Several tests can be carried out to determine whether turquoise is real or fake, but as with most tests, they will cause some damage. The least destructive and easiest method is a scratch test. This measures the resistance of one mineral to being scratched by another.

On the Mohs scale of mineral hardness, turquoise grades 5 to 6. This means it can be scratched by another stone with the same hardness or one that's higher.

Howlite grades 3 to 3.5, azurite 3.5 to 4, and chrysocolla 2.5 to 3.5. Magnesite has a similar hardness to turquoise.

Fluorite grades 4 on the Mohs scale, so it will scratch howlite, azurite, and chrysocolla, but not magnesite or turquoise.

Colour of the Mineral Turquoise

Turquoise was first recorded as a colour in 1573. It's described as 70% blue, 30% green. Turquoise is one of only a few natural minerals to have given its name to a colour.

With regard to the mineral, personal preference for colour varies from one country to the next. In Iran, where turquoise has been highly prized since antiquity, bluer shades are more popular. In Tibet and India, green is the colour of choice.

The colour of turquoise can vary significantly from subtle shades of blue to rich shades of green. Copper is the chemical element responsible for blue, while green is caused by impurities of iron. Although extremely rare, yellow comes from zinc.

The spidery veins, known as matrix, are part of the host rock in which the mineral formed. Pure blue turquoise without matrix is highly sought after.

Turquoise is a relatively soft and fragile mineral. Being porous, it absorbs moisture, which can over time cause irreparable damage. When worn as jewellery, it can also absorb oils from the skin.

The stone's colour can fade if exposed to excessive heat for long periods, and in extreme circumstances, may even crack. Turquoise jewellery should be protected from perfume, hairspray, cosmetics, and other pollutants in the atmosphere. If not wiped off, these substances can leave a residue that can be difficult to remove.

Many of the superstitions associated with turquoise come from its tendency to crack, fade, or change colour.

On the Modern Birthstone Chart, turquoise is the birthstone for December. Blue topaz can be used as an alternative.

The U.S.A., China (including Tibet), Iran, Afghanistan, and Australia are the world's main producers.

 

Article Pictures

The turquoise at the top of our article is from the Sleeping Beauty mine in Arizona. The turquoise in the second from last picture comes from Bisbee, southeast Arizona.  Photos: Courtesy of Stan Celestian.

The turquoise in the second photo, which comes from Kazakhstan, courtesy of Géry Parent. 

The diadem of Marie Louise is from the website of the Smithsonian Museum of Natural History, where it's currently housed. 

The turquoise in the last photo, which is also in the Smithsonian, was taken by Stone Mania.

The white howlite is courtesy of James St.John.

Pop-up photos
Copper, azurite: Courtesy of Stan Celestian. Lapis Lazuli, magnesite: Courtesy of James St. John. Snow Quartz: Stone Mania. Amazonite: Courtesy of Steve Blyskal.