How to identify a synthetic diamond?

Every fifth diamond is artificial. This was announced today by the Russian Ministry of Finance. Gemstone experts told Life how to distinguish a real diamond from a synthetic one. Photo © RIA Novosti/Kirill Kallinikov Deputy Minister of Finance of Russia Alexey Moiseev said that 20% of diamonds sold as real diamonds are not natural. The supply of synthetic diamonds on the world market has become widespread and has even affected well-known jewelry brands. Moiseev also noted that today a special system for marking precious metals and stones is being built in Russia: products will receive a special tag with a two-dimensional code. With its help you can verify the authenticity of the product. But while there is no such system, it is very difficult to avoid the risks of buying synthetic stone.

Everyone wants diamonds

Photo © RIA Novosti/Vladimir Astapkovich An expert at the Gemological Center of Moscow State University, Yuri Shelementyev, said that in a store, an ordinary buyer at first glance will not be able to determine whether the stone in front of him is natural or artificially created. These stones are analogues. Moreover, today scientists can make such synthetic diamonds that they are in no way inferior to real ones. — Diamonds are a brand. Everyone wants them, like dollars. It cannot be said that this stone has any special properties compared to other precious stones. Of course, this is a beautiful stone that has become a symbol of luxury, prosperity and prosperity. This is fashion, and we obey it,” explained Yuri Shelementyev. The brilliance and sparkle of the stones are complemented by the hardness of this mineral, thanks to which diamonds are wear-resistant and do not lose their beauty over the years.

How to choose a real one

Photo © RIA Novosti/Vladimir Astapkovich In the twentieth century there were no synthetic diamonds, there were cubic zirconias. And the buyer could also easily be deceived by slipping him cubic zirconia instead of a precious stone; it is very difficult to distinguish them. Gemologists do not recommend taking the seller’s word for it. You should not be shy and ask to see all the papers confirming the authenticity of the stone. — The buyer must carefully study the information indicated on the product label. If you buy a large stone, ask for its certificate,” explains Yuri Shelementyev. If papers alone are not enough, Vladimir Zhidkov, a member of the National Gemological Association, advises arming yourself with an ultraviolet lamp. You need to illuminate the stone with ultraviolet light. If it glows with a bluish light, 99,9% – this is a natural diamond. If the stone has a green or yellow cast, it is most likely a synthetic cut diamond. — If there is no luminescence at all, it is impossible to simply determine the authenticity of the stone. It is necessary to send it to the laboratory so that specialists can answer exactly what the origin of this stone is,” added Vladimir Zhidkov.

Price is not important

Photo © RIA Novosti / Maxim Blinov It cannot be said that the authenticity of a diamond is determined by its price: a real one is more expensive, and a synthetic one is cheaper. Associate Professor, Department of Gemology, RGGRU named after. Ordzhonikidze Dmitry Petrochenkov noted that the price for a natural one-carat diamond starts at $500. Synthetic diamond may cost slightly less, but not significantly. The price of a diamond is made up of four criteria: carat, quality, color and cut quality. A synthetic stone can be created so well that its value will be higher than the cost of a natural diamond, which is less cut or less transparent. According to Dmitry Petrochenkov, synthetic stone is not a fake. This is a mineral that has a different origin. It has exactly the same qualities as natural diamond. It is very difficult to find good diamonds in nature, so synthetic materials were created. They sparkle no worse. But it’s still better to know whether the jewelry you have is an original or a high-quality copy, so as not to overpay. In the jewelry market, sellers and buyers of diamonds are faced with the urgent question: How to distinguish a real stone from a fake? There are more than 30 types of diamond imitations. A thermal conductivity tester allows you to quickly and accurately identify counterfeits. To identify moissanites, a separate tester was created that works on the basis of electrical conductivity testing. When testing synthetic diamonds with the above-mentioned testers, it may not be enough, since scammers have invented a special coating applied to the stones to deceive the testers. Currently, there are more and more synthetic stones on the market. And if large-sized stones take time to identify them, then checking small ones causes great difficulties, and this is where crafts most often end up. Large quantities of natural diamonds are often mixed with synthetic diamonds, which until recently were extremely difficult to identify. The fact is that, unlike imitations, a synthetic diamond is identical to a natural diamond in physical and chemical properties, so testers based on thermal and electrical conductivity are useless. But there are still some differences that make it possible to recognize a synthetic and natural diamond.

There are two types of synthetic diamonds – CVD (chemical vapor deposition) and HPHT (high pressure high temperature).

HPHT technology has been around for quite some time. Its principle is to create high pressure at high temperatures. Now this technology is used to successfully grow diamonds for cutting diamonds weighing more than 10 carats. These HPHT diamonds can be distinguished by their characteristic metallic luster due to the inclusion of metal particles, which can be seen under a magnifying glass or microscope. They have a specific luminescence – yellowish-green or yellow (in natural diamonds it is either blue or absent). However, recently, diamonds grown using this technology have appeared that do not contain metallic inclusions, with blue or absent luminescence. Stones grown using the HPHT principle may have specific inclusions of metal particles – iron and nickel. In this case, they can be identified using a strong magnet. CVD, or chemical vapor deposition, is a more recent method of growing diamonds. CVD technology, unlike HPHT, does not require ultra-high pressures and industrial capacities, therefore it is applicable in laboratory conditions. With CVD technology, it is possible to finely control the chemical composition of inclusions and the final product, obtaining diamond films on large-area workpieces. In recent years, CVD diamonds have been synthesized and subsequently enhanced with HPHT technology, improving the color of the diamonds by bleaching them, resulting in CVD stones with or without blue luminescence, making the luminescence-based detection method ineffective. You can see internal defects using a 18x-20x-30x magnifying glass or a microscope. When diagnosing a stone using a gemological microscope with a magnification of 80x or higher, you can examine the granularity of the stone.
Natural stone consists of single crystals. Artificial stone is fused single crystals. Like HPHT, CVD can be detected using Fourier transform infrared spectrometry or Romanov spectrometer, as well as using a high-power microscope with specific skill and knowledge. But only serious gemological laboratories have such equipment, which are unlikely to waste time checking small diamonds, since this is impractical. The CLIO company offers the latest world developments that can distinguish a natural diamond from an artificial one. These are portable devices:D-Screen from HRD (Belgium). A device for distinguishing natural diamonds from synthetic and HPHT-processed stones. D-Screen tests stones ranging from 0,2 to 10 carats. Colors range from D to J on the GIA scale. Operates from 110-230 V mains via an adapter or 9 V batteries. Presidium Synthetic Diamond Screener II SDS II uses advanced technology that measures a diamond’s ability to transmit ultraviolet light.
This is a portable tabletop diamond tester suitable for both loose and set stones, including small stones up to 0,02ct. Easy to use and battery operated, blue light indicators indicate the stone is a natural diamond and red light indicates a grown Type IIa diamond. The detector provides accurate results within two seconds. Screen I Smart Pro by Smart ProDIAMOND INSPECTOR from Alrosa ALROSA DIAMOND INSPECTOR uses 3 optical methods to analyze diamonds. Most portable devices only use 1 method. Even heavy and expensive laboratory analytical installations use 1-2 methods. ALROSA DIAMOND INSPECTOR detects colorless and almost colorless:

• Genuine natural diamonds;
• Treated diamonds;
• Non-diamond imitations, including moissanite, cubic zirconia, rock crystal, spinel, amethyst and others;
• Synthetic diamonds from HPHT or CVD grown diamonds (further laboratory testing required).

Diamonds can have a variety of cut shapes and carat weights can vary from 0,03 to 10 carats. Check for diamonds in rings, earrings and other types of jewelry. Convenient holders are included with the device. Less than a minute of analysis to obtain the research result.

The operating principle of the devices is the same – passing short-wave UV light through the stone and measuring the absorption of the wave.

The devices perform diagnostics:

• stones ranging from 1,5 mm wide to 5 mm high (approximately 0,02 to 10 carats),
• diagnoses unframed stones and stones in products, the stone being diagnosed must have an open back for the unhindered passage of a UV ray through it, the duration of the diagnosis is from 2 to 15 seconds.

However, scientific and technological progress in relation to diamond testing also does not stand still. Today, there are a number of manufacturers of equipment for express testing of diamonds.

One such device is the Dia True device from OGI. This device is capable of recognizing both imitation and synthetic diamonds.

The test takes only 15 seconds, all samples are highlighted in characteristic colors. Natural diamonds are blue in color, HPHT is red, moissanite is gray-green with a black center, cubic zirconia is gray-light green, CVD can show yellow, orange, purple, and bright green colors.

This device recognizes all stones 100%. The only thing is that this device is not yet able to distinguish CVD from group IIa diamonds, which also have a violet glow, but these diamonds are quite rare.

Ideally, all stones with a violet glow should be rechecked individually, so this device should be paired with an identifier capable of recognizing Group IIa diamonds.