Black Diamonds — A Hot New Fashion Trend That Could Spell Trouble
By Antoinette Matlins
Black diamonds are not new. They have been a curiosity for centuries, enjoying varying degrees of popularity. While some can be quite attractive, with a very mysterious and alluring character, many people think they look like the inexpensive stone hematite; some natural black diamonds have even been misidentified as this much cheaper stone. They are typically opaque, very heavily included, often with surface reaching inclusions and fractures that mar desirability. They are also very difficult to cut, so you often find them with poor makes. Nonetheless, there have always been collectors of black diamonds and designers who have enjoyed using them to create unusual pieces. Black diamond briolettes have also been much sought after for necklaces and earrings, especially those with an antique look.
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Black diamonds, now very much in vogue, were the center of attention at the major jewelry shows. Pictured is a heart pendant set with black and white diamonds. Photo courtesy Chopard & Cie S.A..
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Today black diamonds are very much in vogue. They were the center of attention at the international gem, jewelry, and watch show in Basel, and they were very noticeable at the JCK show in Las Vegas. Designers all around the world have now “discovered” them and we are now seeing exquisite jewelry reflecting very creative uses of black diamonds, from melee used in spectacular pavé pieces to briolette drops.
So what is wrong with this picture? It’s the failure to disclose that treatments are often responsible for “creating” the black color found in most of the black diamonds currently being used in these interesting jewels.
There is nothing wrong with using treated black diamonds as long as you disclose the fact that the color is not natural. Designers such as Etienne Perret have been using treated-color diamonds for several years to create beautiful, distinctive diamond jewelry that would not otherwise be affordable to most people, and they have always been forthright and truthful with regard to their color not being natural when such is the case. This is not what we are finding with the treated black diamonds so prevalent in the market at this time, and this could spell trouble for anyone selling them. We are even finding them in antique jewelry reproductions and as replacement stones in period antique settings. The current situation can cause some real headaches for anyone who sells them as natural, and can create some very “black” moments indeed!
At the crux of the matter is that many dealers buying and selling them are unaware themselves that what they are buying and selling is treated; they are often purchased from another dealer who either did not know or chose not to disclose the treatment.
The first step to protecting yourself and your customers is to know that this is happening and to take a minute to test the stones to be sure the color is natural if they are represented as such. Fortunately, with treated black diamonds it is usually not at all difficult. Here are some easy tests that will tell you what you really have. If you do not feel confident about doing it yourself, however, be sure to submit any black diamond or jewelry containing black diamonds to a respected gem-testing laboratory for confirmation of origin of color. If buying a manufactured line of black diamond jewelry, you may want to select several pieces randomly for testing.
Tips For Easy Detection
First, natural black diamonds are difficult to cut, so be especially suspicious of pavé jewelry. The cost to cut hundreds or thousands of natural black diamonds in melee sizes so precisely that they can be used in precision pavé work would be very costly, and prices would be much higher than what we are currently seeing. Interestingly, we are seeing just the reverse; melee prices have dropped because supply has increased so dramatically as a result of the addition of the treated material to the mix. Unfortunately, the natural black prices have also dropped because people are unaware that what they are buying is treated, and have not realized how easy it is to separate the natural from the treated.
These simple tests can help you quickly and easily spot treated black diamonds:
• Examine them carefully with a strong maglite or fiber-optic light. If the edges appear deep brown rather than black, it is not a natural black diamond.
• Examine the surface and facet joins carefully with a standard 10x loupe. If the color across the surface seems spotty, or if color is uneven at the facet joins, it is not a natural black diamond.
• Test the diamond with an electronic diamond/moissanite tester, one that offers both thermal conductivity and electrical conductivity testing such as the DiamondNite tester; if the tester indicates the stone is not diamond, you have a treated black diamond.
Note: The stone is diamond, but certain treatments used to alter the diamond’s color to black also alters the stone’s electrical conductivity. Therefore, when tested with the DiamondNite (or other similar tester), the tester indicates that it is an imitation even though it is really a diamond; in this case, it is telling you the diamond is not natural in some way, and indeed, it is not—the color has been altered.
In Tucson this past February, during a demonstration of how to separate colorless synthetic moissanite from a colorless diamond, a man brought a very sizeable “black” stone to test with the tester. The DiamondNite indicated the stone was an imitation and the man became furious. The tester is only for colorless stones because the secondary test measured electrical conductivity and in some fancy diamonds, such as electrically conductive blue diamonds, the reaction might not be reliable. He proceeded to explain that what being was tested was a genuine diamond that he, himself, had treated to obtain the black color. A gentleman with him further explained that during the treatment, the material became very electrically conductive. So while onlookers were unable to mollify the anger of the producer of this treated black diamond, since the stone was, in fact, a diamond and the tester was indicating it was not, a great new test was discovered — one that is very simple and very easy for even a new jewelry salesperson to use to distinguish most of the treated black diamonds now used in jewelry from the natural black diamond.
Diamonds occur naturally in every color of the rainbow, but many colors can also be induced through various treatments. Some are easy to detect while others—such as HPHT induced blue and pink diamonds—require very sophisticated laboratory testing available only at the world’s leading gemological laboratories. Luckily, in the case of black, simple testing is all that is required, so if you take the proper precautions, this is one newcomer that should not be a problem. In fact, properly represented, treated black diamonds and the interesting jewelry created from them offer retailers some distinct opportunities — opportunities that might even provide a competitive edge and help keep business “in the black” !
Antoinette Matlins is a gemologist, lecture, and author of four
popular books including Jewelry & Gems: The Buying Guide. Two new books will be available in September, 2001: Diamonds: The
Antoinette Matlins Buying Guide and Colored Gemstones: The
Antoinette Matlins Buying Guide (GemStone Press).
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