By Lalta Keswani, G.G. and Reema Keswani, G.G., Golconda, New York, experts in fine gemstones, pearls, and jewellery

Since antiquity, gemstones have been an integral part of jewellery. And today, they are still prized for their unique character and intrinsic beauty. But, also since early times, people have found ways to enhance the quality of gemstones, or even create convincing synthetic varieties. At issue now is not so much whether a stone has been treated or created synthetically, but whether this information is disclosed to the customer. While many exhaustive scientific articles have been written on the topic of treated and synthetic stones, this article provides a brief overview of some of the issues involving two varieties of gemstones, quartz and sapphire.

At several recent trade fairs, we were surprised to find that an abundance of synthetic quartz varieties, ranging from rock crystal to amethyst and citrine, were being sold as natural gem materials. We also heard stories about quartz synthetics being sold as natural stones from gem experts, dealers, and retailers alike.

Since some of these trade fairs are sponsored by industry organizations, unsuspecting buyers may be lulled into a false sense of security that the materials on sale are represented accurately and that any treatments were appropriately disclosed. More about this later.

The issue of berylliumenhanced blue sapphires is another landmine and is also relevant because two vendors at a recent trade show represented blue sapphires as “heatonly” (one of the oldest forms of treatment). Yet, we saw clear evidence of high-heat inclusions that are typical of beryllium-diffused sapphires. When challenged on their claims, the vendors admitted to simply have “made a mistake.” Similar treatments are used to “enhance” or change other colours of sapphires, as well.

Beryllium diffusion is an additive process, meaning that the element beryllium is diffused into the stone at high heat, thus changing its colour. Given the significant price difference between “heat only” and “beryllium- enhanced” sapphires, an unwitting purchase of “beryllium- enhanced” sapphires is an expensive mistake to make for retailers and jewellery makers, not to mention the risk to their reputations and legal exposure. What does a retailer or designer do after a piece of fine jewellery is sold, only to learn later that the stone was misrepresented?

In the case of quartz, the appearance of hydrothermal synthetic quartz in the 1970s dramatically altered the landscape. Because the material is naturally abundant, relatively inexpensive, and tends to grow large and clean in nature, there are cost barriers to testing. This is also why most buyers would not think to question the vast quantities—mostly synthetic—available at reasonable prices on the market today. In very clean quartz crystals, even a gem lab with sophisticated equipment may not be able to conclusively state that it is natural or synthetic. In the 1990s, even synthetic ametrine was created, thus complicating an already troubled situation.

As frightening as a sensational headline involving misrepresentation is for a retailer or brand to contemplate, the issues surrounding quartz pale in comparison to the persistent issues with beryllium-enhanced sapphires. There are, however, some clues that may give buyers an indication—for both quartz and corundum—of whether the stone is natural, treated, or synthetic. Using some basic gemmological skillsand a large dose of common sense can give buyers more confidence in their purchases, or signal when they should send stones to a lab for further testing.

Simple Visual Tests: colour, inclusions, zoning

Three simple visual tests are the first line of defence. The first is colour. If you see large quantities of evenly coloured, well-matched parcels of quartz or sapphire at inexpensive prices, be suspicious. Second, look for typical inclusions. For example, the appearance of “zebra stripe” or “soap scum” inclusions in natural amethyst is a diagnostic test for natural amethyst. Inclusions, in general, are arrestingly beautiful. They are microscopic works of art that can be explained and highlighted for your clients as part of the selling process. Synthetic quartz varieties will have tiny granular “breadcrumb” inclusions or “nailhead spicules,” which are liquid-filled channels, terminated by an inclusion on one side.

To continue the above-mentioned example of the two vendors selling blue sapphires as “heat only” at a recent trade fair, when we examined the stones with a 10x loupe, they revealed typical “cotton-ball” inclusions, which indicate dried-out inclusions and very high-temperature treatment. The GemResearch Swisslab (GRS) refers to these inclusions as “fisheyes.” Many experts consider these inclusions to be an important indicator of beryllium-enhanced blue sapphires, but in order to conclusively determine the presence of the beryllium additive (beryllium is a naturally occurring trace element in natural sapphires), the stone needs to be further tested at a qualified laboratory.

Third, look for colour zoning. Natural quartz is the most colour-zoned variety of gemstone while natural sapphires often display angular colour zoning, which is absent in synthetic quartz and corundum. Amethyst and citrine are the most colour-zoned of all gemstones, which can be an important natural indicator, with colour bands and zoning occurring along natural crystallographic angles. On the other hand, most synthetics typically display a more even distribution of colour. In natural quartz and sapphires, which have been subject to heating, the zoning becomes fuzzier, but still maintains its angular structure. Using this short checklist when purchasing quartz material or sapphires may allow you to have more confidence in purchasing these stones, and thus avoid potentially costly mistakes. Since the list involves only the simple technique of magnification, it should be used only as a guide. It cannot and should not be relied upon as definitive in any way. It serves basically to enable you to quickly identify problems for further study or for submission to a gem lab. The more educated buyers are, the better questions they know how to ask.

Just a word about the trade fairs… A few unscrupulous vendors are taking advantage of the self-policing policy at trade fairs. Their lack of ethics, and unsuspecting or too-trusting buyers, can potentially expose retailers and brands to serious reputational risk in the case of quartz, and financial risk given the significant price differences in beryllium-treated versus heated sapphires.

We should all remember the debacle that Macy’s endured recently because of its lack of proper disclosure of glass-filled rubies, and the perils of being featured negatively on a nationally broadcast television show.

What’s in a Name?

Just as a brief aside, there is another storm brewing that involves the reckless nomenclature of various gemstones. To cite a few examples, bowenite is being sold as “Soochow jade” while calcite, serpentine, and soapstone (among other gems) are being offered for sale with the misleading label of “jade.” Chinese buyers are snapping up yellow to brownish-yellow quartzite, which is touted as ‘”Yellow Dragon Jade.” The rise of the Chinese consumer has been akin to a giant awakening and jewellery brands all over the world are scrambling to capture a piece of this huge market. This includes grabbing part of the dizzying price increases surrounding the term “jade”—at any cost.

Gemstones are beautiful, appreciated, and loved. When purchasing them, however, it is important to understand what you are really buying. We cannot stress too strongly the importance of purchasing from dealers you trust and who are committed to full and clear disclosure. But above all, let the buyer beware.