Turquoise is an eye-catching, blue-green stone often used in jewellery. It has been used for centuries within different cultures as decoration, a sign of wealth and status and an object of fascination due to its stunning coloration.
A little known fact is that pieces which people consider to be genuine turquoise have often been processed in some way. This is because turquoise is often a relatively unstable mineral and requires stabilization using epoxy which enables it to be used successfully in jewellery or carved into a decorative item.
Turquoise is an incredibly popular mineral and this makes it a victim of imitation. Most often a mineral called howlite, which has similar characteristics to turquoise, is dyed the distinctive blue-green shade and sold as turquoise. The creation of imitation turquoise actually has a long, illustrious history – it is believed the Ancient Egyptians produced the first turquoise imitations!
Whether you have a turquoise gemstone or a piece of jewellery, or indeed a keen interest in geology and mineralogy, you have come to the right place! We will take a closer look at the properties and characteristics of turquoise, and provide you with a guide on how to tell if your turquoise is real or fake in 5 easy steps.
What Is Turquoise?
If we want to get technical from the off, turquoise is a hydrated phosphate – a compound containing phosphate ions and water molecules – of copper and aluminium. Its chemical formula, in case you are interested, is CuAl6(PO4)4(OH)8·4H2O. It is an opaque gemstone, formed in very specific conditions: arid regions with a slow flow of copper-rich groundwater which gradually seeps downward through the ground and reacts with phosphorus- and aluminium-rich minerals. Usually turquoise deposits are found amongst iron-rich limonite or sandstone.
Microscopic crystals make it a dense, opaque mineral with a fine texture and almost waxy luster when polished up. It is a relatively soft stone, between 5 and 6 on the Mohs scale of hardness. This has made it popular for carving and shaping into items of jewellery and ornaments.
The blue tint in turquoise comes from the copper content of the mineral, while the green tint comes from iron replacing some of the aluminium constituents, or from dehydration (lack of water molecules). The colour of a turquoise sample can vary greatly between almost every shade of green and blue depending on the chemical composition of the sample.
To help make turquoise samples more durable commercially, they are stabilised using epoxy. This also makes them smoother and shinier. Another reason for this is that solid blocks or turquoise are rare and a sample usually contains a matrix of host rock – it is interspersed with the other rock it has formed on, creating a pattern of cracks and so-called impurities. Sometimes a spiderweb matrix is intentionally included in a piece as an attractive feature (like the image below).
What Is Turquoise Used For?
Turquoise has been highly valued and widely utilised throughout human history. In fact, it was among the first gemstones that were mined by people. As a fairly soft stone it can be carved into figurines and sculptures, set into jewellery, and displayed as art pieces.
It has been used symbolically as a symbol of wealth and status in ancient civilizations including the Ancient Egyptians and Aztecs, and in Mesopotamia. Some of the most astounding uses for turquoise were as ritual masks, knives and shields used by the Aztecs. Eventually it was traded up and down the Silk Road, spreading its popularity throughout Europe and Asia.
In Persia turquoise was inlaid into important objects and buildings like mosques. Many civilisations throughout history have regarded it as a holy stone which carries great symbolism.
Native American people have a long and meaningful association with turquoise. They historically and presently use it in traditional jewellery, mosaic inlay, and carved talismans.
Nowadays, turquoise is most commonly used in jewellery in the form of cabochons (a smooth, rounded gemstone), flat inlays, or beads for a whole range of items including necklaces, bracelets, rings and earrings.
Where Can Turquoise Be Found?
Many people associate turquoise with Iran because the Nishapur district produces the world’s most famous and greatest quality turquoise stone. This country has been an important turquoise source for more than 2000 years.
The Sinai Peninsula of Egypt is another important location and has been used to mine turquoise since, or possibly even before, the Ancient Egyptian era.
The south west United States is also home to vast turquoise deposits. Two key deposits in California and New Mexico were mined by pre-Columbian Native American people. Arizona and Nevada produce the greatest amount of turquoise commercially today.
The History Of Turquoise Imitation
Ancient Egyptians were potentially the first civilization to produce turquoise imitations. They produced specially glazed earthenware pots called faience in an attempt to imitate turquoise. Other incidences of fake turquoise through history have been turquoise-colored enamel and porcelain, and even wood which has been painted with malachite paint or coloured glass.
Interestingly, fake turquoise was not necessarily frowned upon in history. Turquoise was a symbolic stone for many people and if they could not obtain or afford it they were very happy to find a proxy for turquoise. For many, the colour was important rather than the value of the material used.
How To Tell If Turquoise Is Real
Do you have a beautiful turquoise sample and would like to find out if it is real or not? You are in the right place. Here, we will set out some easy steps to help you identify whether you have real turquoise or not. But first it can be useful to check out some of the biggest culprits of turquoise imitation – dyed howlite, and plastic or resin.
It has been estimated that around 90% of fake turquoise globally is actually dyed howlite. Originally, howlite is white and possesses darker mineral veins which look very similar to genuine turquoise veins (A.K.A. matrix). When dyed a stunning turquoise shade it bears a very strong resemblance to real turquoise. See an example of howlite and turquoise being used together in a necklace in the image below.
This kind of fake turquoise is super common in fashion stores and boutiques. It is usually easier to tell a plastic or resin piece from a real piece by weight – plastic turquoise is much lighter than the real deal. But beware, metal is sometimes added to the inside of the stone making it much heavier and confusing the unwary buyer.
So let’s take some steps and perform a few easy tests to help you on your quest for genuine turquoise!
1. Colour And Texture
Genuine turquoise will naturally fade with age! If you have had your turquoise piece for a good while and you think it may have faded in color intensity it may be real turquoise. The colour of genuine turquoise can vary greatly and depending on the region of the world it was mined from, so colour may not be the best indicator.
In terms of texture, turquoise has a smooth, almost waxy texture and a dull luster when polished. If your piece has cracks, try running your fingernail over them. If you can’t feel any ridges or slight indentations the cracks may have been painted on, indicating an imitation material.
Try to weigh your turquoise piece in your hand. Does it feel heavy and dense? Or strangely light for its size? If it feels very light it is likely to be plastic or resin. But be warned, metal is sometimes imbedded in the centre to make the piece feel heavier. A simple way to solve this one is to use a match or lighter and gentle hold it to your turquoise. If it starts to smell of burnt plastic or even to melt a little, it is not real turquoise.
If the price of your piece was suspiciously low it is almost 100% definitely fake turquoise. Real turquoise can be very expensive because of its rarity, and how difficult it is to process copper- and aluminium- and/or iron-rich minerals. If you find a turquoise necklace or bracelet for somewhere around $20 or less, it is very likely imitation turquoise.
Per carat, turquoise usually ranges between $1 and $10 USD per carat. Although samples of the absolute best quality turquoise can be sold for up to $1000 USD per carat!
4. The Scratch Test
Turquoise is categorised as between 5-6 on the Mohs scale of hardness. This means it can potentially be scratched by a simple kitchen knife, or if it is a higher quality turquoise it can only be scratched by a steel nail. So first, try to scratch the piece with your fingernail. If it scratches it’s not turquoise. Secondly, try scratching it with a coin. Again, if it scratches then it is not turquoise.
Howlite is softer then turquoise so it is likely to be more easily scratched than turquoise. We recommend scratching a part of the piece that is not visible like the underside. Just because it is not real turquoise does not mean its not pretty! You don’t have to ruin your jewellery or ornament in your quest for real turquoise!
5. Acetone (Nail Varnish Remover)
This step is an important one if you suspect your turquoise is actually howlite. By applying acetone (found in everyday nail varnish remover) on a bit of cotton wool or tissue to your piece, you will be able to see if it has been dyed or not. If it is a piece of dyed howlite the turquoise colour will start to be removed. If the colour stays put it is definitely not howlite and may well be turquoise.
Again, we recommend applying acetone to an area of the piece which is not visible. The dye used on howlite does not penetrate the surface so the piece will be returned to white with the application of acetone.