Turquoise is one of the oldest of all gemstones and it's also one of the most popular. Used extensively in jewellery by many cultures around the world, it's one of the very few minerals to have given its name to that of a colour.
The history of turquoise can be traced back as far as 6000 BC. where records from the reign of the Pharaoh Semerkhet detail extensive mining operations that involved thousands of workers. It was mined in the Sinai Peninsula and many beautiful artefacts were subsequently found in Egyptian burial chambers dating from 3000 BC. Beads discovered in Egypt were dated to 4000 BC whilst a discovery in Mesopotamia (present day Iraq) was dated to 5000 BC. The most famous artefact has to be the burial mask of King Tutankhamun which as well as turquoise featured lapis lazuli, quartz, carnelian, feldspar, other gemstones and coloured glass.
Archaeologists also found imitation turquoise artefacts from this same period and it's generally believed this gemstone is likely to have been the first to have been imitated. Cheaper substitutes have been produced throughout history and it's a practice which continues to this day. The mineral howlite is widely used as a substitute because it's relatively cheap and has a similar texture. This greyish white coloured stone is porous which makes it easy to dye and more importantly it exhibits dark spidery veins which to the untrained eye, could be mistaken for the matrix that's often present in turquoise. Today there is a huge amount of fake material on the market and sadly many people will be blissfully unaware that their piece of turquoise may not actually be genuine. Howlite is even sometimes marketed as white turquoise which doesn't even exist.
Turquoise was first recorded as a colour in 1573 and officially it's 70% blue, 30% green yet as a mineral it can vary from sky blue to blue/green to apple green. Copper is responsible for its blue colour whilst shades of green are caused by iron, yellow although rare is due to the presence of zinc. The familiar dark spidery veins which are correctly known as matrix are part of the host rock in which the turquoise evolved. Pure blue gemstones void of matrix are highly sought after and can command exceptional prices.
On display in the Smithsonian Natural History Museum, Washington D.C | Photo: Stone Mania ©
Turquois meaning "Turkish Stone" was the name given to the mineral by the French in the 17th century in the belief that it had originated from Turkey but in fact, it had just passed through there on its way to Europe after having been mined in the North East of Persia (modern day Iran).
The Ancient Roman author and philosopher Pliny the Elder wrote about turquoise in his works Naturalis Historia published around 77 AD and referred to it as callais or callaina. The bible identifies it as the first stone in the second row of the High Priest's breastplate which is a religious garment worn over the top of a tunic.
Colour preference varies from one country to the next, in Iran where its been highly prized since antiquity the bluer variety is favoured yet in Tibet and India greener stones are more popular. Turquoise was being mined as early as 1000 AD in the Americas and was used extensively by the Inca, Aztecs and Maya. It has always been revered by American Indians including the Navajo, Apache, Zuni and Pueblo and it's the most important gemstone used in traditional jewellery which is crafted in silver as opposed to gold. 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 which was made by the French jeweller Etienne Nitot et Fils of Paris. It originally featured emeralds and diamonds set in gold and silver but in 1953 it was sold to Van Cleef and Arpels who at some point between 1956 and 1962, replaced the emeralds with seventy nine Persian cabochons. The emeralds were subsequently sold in other pieces of jewellery and were promoted as being gemstones from the historic diadem.
Marie Louise's diadem on display in the Smithsonian, Washington D.C
On Mohs scale of mineral hardness hardness turquoise is graded 5 to 6 so it's quite fragile and also porous so moisture or oils from the skin can be absorbed causing irreparable damage. Turquoise will also lose or change colour if exposed to excessive heat.
Turquoise is one of the birthstones for the month of December with the other being citrine. The USA, Tibet, China, Afghanistan and Australia are the world's main producers.