Turquoise: One of the World's Oldest Gemstones

Turquoise is one of the oldest and most easily recognised gemstones. Prized for its distinctive blue-to-green colour, it has been used for jewellery and decorative objects for around 9,000 years. This article looks at what turquoise is, how it forms, its long history and how faience was used in ancient Egypt to replicate its colour and appearance.

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 occurs more commonly in massive form, as compact aggregates in which individual crystals cannot be distinguished.

Turquoise is a secondary mineral formed through the weathering of other minerals. It typically forms in veins, nodules or crusts within a host rock.

In arid regions, rainwater carrying dissolved copper moves through the ground and reacts with minerals containing aluminium and phosphorus. Over time, these reactions can produce turquoise.

The name 'turquoise' comes from the French pierre turquoise, meaning 'Turkish stone'. Turquoise did not originate in Turkey but passed through there on its way to Europe. Much of it was mined in northeastern Persia, now Iran.

The spidery veins in turquoise, known as matrix, are remnants of the host rock in which this mineral formed. Turquoise without matrix is highly sought after.

Turquoise is relatively soft, fragile and porous. It can absorb moisture, oils from the skin and substances found in cosmetics and perfume, which can gradually alter its appearance.

The stone's colour can fade if exposed to excessive heat for prolonged periods and, in extreme circumstances, it can even crack.

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

Turquoise was first recorded as the name of a colour in 1573. It's one of only a few natural gem materials to have given its name to a colour.

The shade can vary from pale blue to green. Copper is the chemical element primarily responsible for its blue colour, while increasing amounts of iron can produce greener shades.

Preferences for colour vary between countries and collectors. In Iran, strong blue shades have traditionally been preferred. Green turquoise has long been valued in Tibet and other parts of Asia.

On the Modern Birthstone Chart, turquoise is a birthstone for December.

Important sources of turquoise include the U.S.A., China, Iran, Afghanistan and Australia.

Turquoise Throughout History

Some of the earliest known evidence of turquoise being used dates to around 9,000 years ago.

At Jiahu in Henan Province, China, more than 1,000 turquoise objects have been discovered, predominantly ornaments, dating from approximately 7000 to 5800 BC.

Turquoise beads dating to about 7000 BC have also been found at archaeological sites in western Iran. Although Iran would later become one of the world's most important sources of turquoise, the origin of these early stones has not been established.

Evidence of turquoise mining appears later in Egypt. Turquoise was being mined by the fifth millennium BC. Between approximately 4400 and 3100 BC, people from the Nile Valley were exploiting turquoise deposits in the southwestern Sinai.

Mining later developed into organised expeditions involving large numbers of people and supplies. Archaeological remains and inscriptions in the Sinai provide evidence of miners, officials, transport animals and provisions required to sustain expeditions into this remote desert region.

Turquoise may have been used or mined earlier than the dates currently known, but no archaeological evidence has yet been found to establish this.

One of the most famous artefacts to feature turquoise is the funerary mask of King Tutankhamun. This priceless work of art is decorated with lapis lazuli, turquoise, white quartz, carnelian, amazonite, other gemstones and coloured glass.

In the Bible, turquoise is said to have been the first gemstone in the second row of the high priest breastplate. This religious garment was worn over a type of tunic.

Turquoise has long been revered by Indigenous peoples of the American Southwest, including the Navajo, Apache and Ancestral Puebloans. It has been mined and traded in the region for centuries and remains central to several Native American jewellery traditions. Turquoise was also widely used by the Inca, Aztec and Maya civilisations.

Napoleon I gave his second wife, Empress Marie Louise, 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. At some point between 1956 and 1962, the emeralds were replaced with seventy-nine Persian turquoise cabochons. The emeralds were subsequently sold in other pieces of jewellery and promoted as having come from the historic diadem.

The turquoise diadem is now housed at the Smithsonian.

Turquoise was highly prized in ancient Egypt but was relatively rare. Its distinctive blue-green colour was so valued that the Egyptians reproduced it using manufactured materials.

The most important was faience, made primarily from finely ground quartz or sand with mineral salts and lime, which developed a glass-like surface when heated to a high temperature in a kiln.

Faience appeared in Egypt by the late fifth millennium BC and was commonly coloured using copper compounds. It was used extensively for beads, amulets, inlays, figurines and other decorative objects.

One theory is that faience may have been developed partly to produce a material with an appearance similar to rare blue and blue-green stones, particularly turquoise. The resemblance was not just superficial. Beneath the coloured glaze, the irregular particles of crushed quartz scattered light, giving the material an appearance of depth, brightness and translucency that closely resembles the optical qualities of natural turquoise.

Egyptian faience was known as tjehenet, a word associated with brilliance, gleaming or dazzling. Blue-green was particularly important because the colour was associated with life, fertility and regeneration.

Turquoise formed part of a characteristic Egyptian jewellery palette alongside red carnelian and dark blue lapis lazuli. When natural stone was unavailable, other stones and manufactured materials could reproduce these colours. Faience therefore provided both the appearance and symbolic colour associated with precious stones.

Although it's sometimes claimed that fake turquoise was produced in ancient Egypt, there is no evidence that it was intended to deceive people into believing it was genuine turquoise.

Faience became a highly valued material in its own right, particularly because of its colour, brilliance and symbolic associations. Glass was later used as another means of reproducing the colour of turquoise.

Today, the market is flooded with fake turquoise, much of which is produced in China. In an article in our blog, we look at the materials commonly used to imitate turquoise and how to identify them.

Ancient Roman author and philosopher Pliny the Elder mentioned what historians believe may have been turquoise in Naturalis Historia. Published around 77 AD, he refers to stones called 'callais' and 'callaina'.

He described 'callais' as "like sapphires in colour, only that it is paler and more closely resembles the tint of the water near the sea-shore."

The word translated as "sapphires" is sapphirus. It was later established that the stone Pliny was actually describing was lapis lazuli. He described sapphirus as a blue, opaque stone in which gold appeared to glitter as tiny spots. What he believed to be gold was almost certainly pyrite, a distinctive mineral within lapis.

He also noted that some pieces contained hard particles, making them unsuitable for engraving. Pyrite is a hard metallic mineral that would have been difficult to cut. Therefore, lapis containing a large amount of pyrite would have been far more difficult to engrave.

Another material he described, also believed to be turquoise, was 'callaina'. He described it as pale green, with the finest material coming from Carmania, an ancient region of present-day Iran. He states that it was particularly prized when worn around the neck or on the fingers, and that setting it in gold enhanced its appearance.

Pliny also observed that better quality material could lose its colour upon contact with oil, perfume or undiluted wine and that the stone was readily imitated in glass. Although these descriptions strongly resemble the mineral turquoise, the precise identification of these names remains uncertain.

Article Pictures

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

The turquoise in the second photo is from the King Turquoise Mine, southern Colorado. Photo courtesy of Ron Wolf.

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

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

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

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

The photos in our article and the links for the pop-up photos link to the original image on Flickr. You may only be able to view them if you join. Joining Flickr is free, with no additional charges.