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TURQUOISE TREATMENTS AND FAKES |
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TURQUOISE TREATMENTS AND DIFFERENT TYPES OF TURQUOISE ON THE MARKET Most of the turquoise on the market today is has been treated with plastic bonding, chemical vapor penetration, paraffin or some other stabilizing agent to help the material retain its bright color. It is estimated that less than 10% of mined turquoise can be used without some sort of treatment - though this does vary somewhat from mine to mine. Without treatment, most turquoise will absorb chemicals from its environment and change to a greenish color over the years, owing to the porous nature of the gem. Nevada turquoise is generally higher quality and often a much lower percentage of the mine production requires treatment. There has long been a strong demand for high quality turquoise, and the supply has never really been able to satisfy the demand. Years ago it was discovered that soft, light colored turquoise soaked in a liquid plastic resin would absorb the plastic into the pore spaces. This treatment produces a material of a deeper color, and when the plastic is hardened, a much stronger stone. The once poor quality pale material then ends up appearing somewhat like the best grades of turquoise (or at least a lot closer to it). This was nothing new as turquoise had been treated with animal fat or various waxes thousands of years ago, and although these treatments did not provide the added strength or permanence of plastic, they had the same effect on the stone's color. The words treated and stabilized basically mean the same thing when it comes to turquoise. They describe the same type of process, and there are several methods for impregnating soft porous turquoise with liquid plastic and hardening or stabilizing it. There is also a newer processes being used today is called 'enhancing'. This process actually adds silica to the the turquoise, intensifying its hardness and color. As with the plastic, this treatment adds new material to the stone, even though the actual chemical structure of the turquoise does not change. |
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| NATURAL TURQUOISE: This means a stone that has
had no alteration to its composition. Such stones are merely cut into shapes and polished
before being mounted in jewelry. Natural turquoise remains slightly porous, as all natural
stone is to some varying degrees, and it may tend to change color over time as it is worn
and handled. Generally, fine gem quality natural turquoise is harder and more durable than
other stabilized or synthetic types. Some of the finest natural turquoise in the world
comes from the state of Nevada.
STABILIZED TURQUOISE: This means that the natural mineral has been altered to harden the stone, usually by infusing polystyrene plastic resin into the pore spaces within the stone. The stabilization process serves to "lock in" the color of the stone so it will not change. A considerable amount of turquoise from China has been treated by oiling or waxing. This results in a MUCH inferior product as the oils or waxes are not nearly as permanent or strong as plastic resin. Both oils and waxes will degrade over the years and this type of turquoise will often yellow even if it is not worn and is kept in a drawer. Unfortunately, the effect of oil or wax on the gem's color is initially the same, so there is no easy way to tell how a stone has been treated - until years later. This is a point where it is important to know the dealer and buy from someone who really knows their turquoise. One of the main reasons is that the value of stabilized material is roughly 1/10th the value of equivalent natural gem material. A pin highly heated in a flame, touched to the back of a treated stone will give off the odor of plastic or resin as the heat of the pin vaporizes some of the stabilizer. |
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| COLOR-TREATED TURQUOISE: This is a process the same as stabilization but a color dye is added to enhance the stone's color. It is also known as color-enhanced or color-infused turquoise. This process uses chalky, pale blue material which is very soft. Treated turquoise is best recognized by its translucent plastic appearance. It looks unnatural because it appears too blue and too highly polished. Treated turquoise, since it is soft originally, can be easily scratched with a hard knife blade. High quality gem turquoise cannot be scratched with a knife. | |
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| RECONSTITUTED TURQUOISE: This is the name used
for a material that consists of turquoise powder and chips that are mixed with plastic
resins and coloring agents and compressed into a solid "loaf like" form. It has
an appearance much different from natural turquoise and only resembles genuine
turquoise only in a general kind of way. Recently, some oriental manufacturers
are taking chalky, porous turquoise, mixing it with resins and various materials
to simulate matrix, then adding odd, unnatural coloring agents to achieve "pepto"
pink, purple, bright yellow, apple green, red and other strange colors. Some of
these color combinations are very unnatural but truly unique. Because they
contain at least a small percentage of low grade turquoise somewhere in the mix,
they are sold by disingenuous manufacturers simply as turquoise (without any
further explanation of the strange dyes, plastic resins and other treatments). This material is
of little gem value, but is sold to uninformed buyers as if it were something of
significant worth - the savvy buyer should beware of this material. SIMULATED OR IMITATION : This is an imitation turquoise that is pure plastic which is colored to a turquoise type tone with a blue pigments. It contains no actual gemstone whatsoever. It is usually pressed or molded together, and is sometimes referred to as "block turquoise". Sometimes small pieces of various materials including pyrite are sometimes added to imitate turquoise matrix. This material looks even less like natural turquoise than the reconstituted variety. Although sometimes sold by the dishonest to the unwary as the genuine article, imitation turquoise is really suited only for costume type jewelry. I have seen this material for sale in Mexico, set in silver sold to the unwary tourist. |
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The treating of turquoise cannot be condemned and it is
certainly not wrong to buy or sell it; but it is wrong to misrepresent it or to
fail to inform the buyer and mislead
people. It is not nearly as valuable as natural gem turquoise. Folks who buy treated
turquoise that has been oiled or waxed rather than plasticized may find problems several
years after their purchase as the waxes or oils begin to degrade and yellow. Treated turquoise
should always be clearly labeled and sold as treated or stabilized and should not hold the same status and
value of natural gem turquoise, which is the true gemstone. Roughly 90 percent of all
turquoise mined is stabilized or enhanced in some way before it is set in jewelry.
Turquoise that is softer, porous and chalky and will not hold together by itself. Treating
the stone in this way makes it darker and harder, and less likely to fall apart or crack
when worked. To complicate the subject even further, there is high-quality turquoise that
is stabilized due to the seam-structure in the stone that might fracture if not treated.
This turquoise is too hard to absorb the plastic, most of it settles in the matrix
cracks. It pays to know what you are buying when it comes to gemstones. We mine all of the turquoise offered on our web site. We took it from the ground, so we know its history and what's been done to it. If we state that the turquoise is untreated and natural, we know and can guarantee it with certainty. We make all of our own jewelry with our own rough. That way we can fully guarantee the quality and authenticity of both our jewelry and stones. The best guarantee the buyer can have is to deal only with a reputable dealer that you can trust, and we can offer you the confidence and assurance you need. THE
TURQUOISE INFORMATION PAGE
TURQUOISE ROUGH |
Please note that the author, Chris Ralph, retains all copyrights to this entire document and it may not be reproduced, quoted or copied without permission.
NEVADA OUTBACK GEMS TURQUOISE AND JEWELRY
