Did you know that 90% of the Turquoise on the market is actually dyed Howlite? Howlite is an absorbent white mineral that can be dyed in almost any color imaginable. So how do you tell the difference? The ideas we will discuss for telling them apart are:
The Egyptians were fond of Turquoise, as where the Chinese. In fact Turquoise has been discovered that was carved by Chinese artisans over 3,000 years ago. The Persians (modern day Iran) had the biggest Turquoise market on the planet. 2,000 years ago they were trading in this beautiful gemstone that was pulled from the nearby mountains. The Persians believed that the blue color of Turquoise represented the heavens. You will notice in present day Iran that many of the temples and places of worship will have Turquoise embedded into the entrance.
The native American Indians also had an eye for Turquoise. There is evidence that the Navajo Indians had Turquoise mines that are ancient. The Navajo Indians made the Turquoise a central focus of some of their beliefs. One of the beliefs was that Turquoise thrown into a river can cause it to rain.
Like all things with gemstones and cheaters, it is far more profitable to sell something that looks like Turquoise. Something that is much cheaper to produce. Throughout history the finest color of Turquoise has always been the Persian Turquoise. An incredible robins egg blue color that is unmistakable for any other gemstone. This color was sought after by Kings, Queens and rulers of Empires. This of course made this particular color of Turquoise extremely expensive and hard to find.
The beauty of Howlite is that it can be dyed any color imaginable. The most common color you will see it dyed is of course the Robins egg blue. The same blue that the Persian Turquoise is known for. This way the cheaters can sell the imitation Turquoise for a high price and get the most profit.
The other benefit of using Howlite is the natural webbing or matrix that occurs in this mineral. It is almost identical to the webbing in natural Turquoise. Since this webbing is basically impossible to manufacture it is easier to use an existing mineral that has the same properties. Below is a side by side picture of white Howlite (this is how it looks naturally), natural Turquoise and dyed Howlite. You can see how similar the webbing and matrix look.
Firstly, lets get a grasp on how this mineral forms. The main element that causes the blue color is Copper, so we need some of that. Next up is a mixture of water, aluminium and phosphorus. Once all of those ingredients are together in the same place at the same time the formation of Turquoise can occur. The different amounts of these elements can change the properties of Turquoise dramatically.
It is very rare to find Turquoise with a perfectly uniform and evenly distributed color. The old stones coming from Persia certainly had even color but that is why they are worth thousands of dollars. Stones that are very uniform in color are more than likely dyed.
The matrix is the most obvious inclusion in Turquoise. So where does it come from? It is the left over remains from the host rock in which the Turquoise grew. The webbing can be black, brown, yellow or a host of other colors. Over long periods of time this matrix erodes away. When this happens the matrix and the Turquoise are at different heights and this creates a type of over growth.
This is the first physical observation you can make. If you have a rough natural piece, use your finger nail to rub along the surface of the stone. If your nail gets caught on where the Turquoise meets the webbing, then this is a good indication of natural Turquoise.
The next observation you can make is about the hardness of the mineral. Howlite has a hardness of about 3.5 while most Turquoise is between 5 – 6. While this is not an easy way to tell the difference, if your stones scratch easily then they are more than likely dyed Howlite.
This next test is known as a ‘destructive test’. If your Turquoise is dyed this test may damage the stone. All you need is some acetone (nail polish remover) and a cotton bud or a piece of tissue. Acetone is extremely handy for checking if anything has been dyed. Simply place some acetone on a cotton bud and wipe an area of the stone. Choose an area that is insignificant such as the back of the stone or right on the edge. Once you have wiped the stone the cotton bud should turn blue and the stone should appear to have a whiter patch or an area of lighter color.
The dye used on Howlite only penetrates the surface of the stone. The inside is still white while the outside is a vibrant blue. Some very cheap dyes will actually run with a bit of water added to it. These are the cheapest versions and many people complain about their pieces losing color during raining days.
Lastly there is one way to tell if your Turquoise is natural or dyed. That is the price. If it seems too good to be true, then it probably is. Take for example a strand of perfectly matching amazing blue Turquoise beads. In nature it would be very difficult to find a bunch of Turquoise beads that have exactly the same color.
The biggest piece of advice to give when buying Turquoise is to try and find someone you trust. Ask them where the stones come from, get a feel for how much knowledge they have. A place like Gem Rock Auctions monitors the active auctions to make sure all of the Turquoise on the site has the correct treatments labeled.
Was this article helpful?7 people found this article helpful
Wonderful presentation, I have been telling my clients for years to watch for this type of Misrepresentation of the Turquoise, I always tell my howlite clients how the gem is often used and dyed to look like Turquoise. Love your Presentation and thought this was very informative for those who love gems and want to learn every fact they can possibly find, ‘that is fact’.
Karen Del G
Extremely useful information, Ross. Now I am sure that the Sleeping Beauty turquoise I purchased from a well-known television and online jewelry retailer is a howlite. I have suspected the legitimacy of the turquoise ever since I received it three years ago.