How to distinguish cubic zirconia from moissanite?

What is a diamond? This is a cut diamond, which is a natural form of carbon, with a special structure of the crystal lattice. Because of this crystal lattice, diamond is not only the hardest substance on our planet (and possibly beyond), but it also sparkles! Who doesn’t love shiny things? Almost everyone loves them! A diamond, a very nice-looking thing, but too expensive. That’s why they’ve been trying to counterfeit it since ancient Rome. Of course, these were naive attempts to pass off glass or natural zircon stone as the hardest mineral on Earth. This worked with varying degrees of success until the twentieth century arrived. Diamonds began to be replaced with all sorts of yttrium-aluminum garnets, strontium titanates and other rutiles. True, it was not possible to achieve resemblance to a diamond. Any jeweler who has the slightest knowledge of stones has seen a fake with the naked eye. The first trouble came from an unexpected source. In the 1970s, a group of Soviet scientists led by V.V. Oshiko synthesized a substance scientifically called cubic zirconium dioxide. This significant event happened at the Physical Institute of the Academy of Sciences (Physical Institute named after P. N. Lebedev of the USSR Academy of Sciences). The new material was named after the first letters of the name of the institute “FIANit”. Now cubic zirconia or CZ (Cubic Zirconia) is well known to all jewelers. However, in the 1970s it caused panic. It is almost impossible to distinguish a diamond from a cubic zirconia if both are fixed in a piece of jewelry. The difference is not visible at all to the naked eye or through a magnifying glass. In addition, cubic zirconia shines brighter than a diamond, which makes comparison even more confusing. This would have been a very big nuisance for jewelers if one very unusual property of the diamond had not been revealed – extremely high thermal conductivity. Diamond conducts heat several times better than silver – a recognized leader in this segment of physics. Very quickly, portable devices were created that make it possible to reliably distinguish cheap synthetic cubic zirconia from expensive natural diamonds in a matter of minutes. Jewelers came to their senses and peace and grace came to the diamond market. A few years later, the disadvantages of cubic zirconia were also discovered: due to the low hardness of 8 – 8.5 on the Mohs scale (sapphires and rubies are 9.0, and diamonds are 10.0 on the same scale), the edges of the synthetic stone chipped off after some time, and it stopped shining. By the way, by this specific feature it is very easy to distinguish cubic zirconia from a diamond. If you have a piece of jewelry that has clearly been used, then just look at the stones with a magnifying glass. If the edges of the stones are sharp, then they are probably diamonds, and if they look “bitten”, then they are cubic zirconia. Among other things, cubic zirconia is easy to scratch with corundums, which include sapphires and rubies, including synthetic ones, but it is impossible to scratch a diamond or corundum with cubic zirconia. The second jewelry trouble happened in the late 1990s. Jewelry with diamonds, which, upon careful examination, were not diamonds, were sold en masse to pawnshops, thrift stores and thrift stores. Diamond thermal conductivity testers showed that there was no doubt that there was a diamond in the jewelry, and the stone looked like a diamond – it sparkled gorgeously, was very hard, did not crumble and left scratches on the sapphire. However, the new unknown stone had nothing to do with natural diamonds. The new stone that the jewelry world encountered turned out to be not so new – it is called MOISSANITE and has been known to the world for about 100 years. The history of this stone began quite a long time ago, back in 1893. It is associated with the name of the great French chemist-mineralogist, Nobel Prize winner in 1906, Henry Moissan. One day Mr. Moissan came to the United States to explore Devil’s Valley in Arizona. This place is a site where a meteorite once fell and a French chemist decided to look for something unusual in the crater. The unusual did not take long to happen – he found diamonds. However, in 1904 it turned out that these were not diamonds at all. It turned out to be a very exotic substance – “silicon carbide”. At that time, humanity was not familiar with such a mineral. Henry Moissan discovered material of extraterrestrial origin. In honor of the discoverer, the new mineral was named “moissanite”. Until the mid-1950s, it was believed that moissanite did not occur on Earth. However, in the late 50s, it was found in microscopic quantities in natural diamonds. Moreover, it turned out that one Swedish chemist, part-time baron, Jones Jacob Berzelius, allegedly managed to accidentally synthesize silicon carbide at the beginning of the XNUMXth century. In 1998, a jewelry variety of synthetic moissanite was introduced for the first time. The natural color of moissanite is intensely green, and only with incredible efforts can this color be almost completely removed so that the synthetic stone begins to resemble a diamond of IJK color, and in the best cases GH. Actually, in 1998 the triumphal march of this stone began around the world. True, unfortunately, too often moissanite became the main participant in criminal and fraudulent stories. Having the same thermal conductivity as a diamond, moissanite has long misled jewelers and pawn shop appraisers. As always, the solution to how to distinguish a diamond from moissanite turned out to be simple, you just had to look hard. Moissanite conducts electricity well, which is something natural diamonds never do. True, today there are already isolated cases where a diamond for some reason still conducts electricity, but these are the rarest exceptions to the rule. In the mid-2000s, a combined device appeared on the market that measures first thermal conductivity and then electrical conductivity and reliably distinguishes a colorless diamond from moissanite. The “colorless” clause is there for a reason. Diamonds, as you know, come in all possible colors, including black. So, in most cases, a black diamond also has electrical conductivity due to the extensive internal graphite zones, which makes testing a black diamond with such a device absolutely pointless. In August 2015, the US patent on the moissanite production process expired. In this regard, we can expect that mass production of this material will begin all over the world. Moissanite is a very beautiful and exceptionally hard stone (9.5 on the Mohs scale), unlike cubic zirconia. In addition, moissanite shines even more than diamond and cubic zirconia combined. Its most important difference from a diamond is the price. According to various estimates, the cost of moissanite ranges from 5 to 10% of the cost of a diamond with similar characteristics. But don’t let anyone be confused by the low percentage figure. If a 1 carat diamond with clarity VS1 and color I costs approximately $5500, then 5-10% for a similar moissanite will be $250 – $550, which is also a lot. For comparison: cubic zirconia, similar in size and characteristics, will cost no more than 40-50 rubles. In 2016, moissanites were introduced that match the color palette of EF’s top diamonds. Such moissanites are extremely expensive, and they are presented on the market in small quantities. Actually, what was all this conversation about? If the seller tells you that you are purchasing jewelry with moissanite, then no problem – this is your informed choice. You pay adequate money for jewelry with moissanite. However, be careful when moissanite is offered for sale under the guise of a natural diamond. When buying expensive jewelry with a diamond, always double check everything yourself ten times (if you know how) or call a professional gemologist for the deal. Inside moissanite, bifurcated edges are sometimes visible. This optical phenomenon has never been observed in a diamond. This is one of the simplest diagnostic signs that allows you to distinguish a moissanite from a diamond, which is called “on the knee”. True, if this moissanite was produced in the USA and cut along the optical axis, this effect will not be observed in it. In recent decades, technologies for the artificial cultivation of precious stones and their analogues have been actively developing. Of course, most of all, manufacturers, jewelers, and buyers are interested in the possibilities of producing the king of precious stones – diamond, which is due to its price. The high price of natural diamonds is associated, first of all, with their properties, such as phenomenal hardness, excellent ability to refract and return light, which ensures the sparkle and play of a cut diamond. But there is another important factor – significant monopolization and closure of the diamond mining market, which does not allow the price of stones to fall according to the natural market laws of competition. Recently, laboratories have developed several technologies for growing synthetic diamond, the most common two of them:

1. In a chamber at high pressure (50-60 kilobars) and temperature (about 1400-1600 degrees Celsius), which has the abbreviation HPHT (High Pressure, High Temperature), growing an artificial diamond of about 1 carat using this technology takes about 5 days.
2. Chemical deposition (CVD). The most popular variation of this process is microwave plasma vapor deposition (MPCVD), using a mixture of methane and hydrogen gases as the starting material.

Manufactured artificial diamonds have a number of disadvantages:

Lowest prices for moissanite in Russia

1. The main drawback is the color. It is quite easy to synthesize richly colored stones (yellow, blue, green, pink, etc.), but the problem of producing perfectly colorless diamonds still remains unsolved. A standard artificial diamond has an IK color on the GIA scale, which corresponds to color 6-7 according to the Russian TU standard. This means that the synthetic diamond has a clearly visible yellowish tint. Recent advances in HPHT and CVD technologies have made it possible to obtain GH color, i.e. 4-5 color according to specifications, but the complexity of production does not yet allow the prices of such stones to drop significantly below the prices of natural diamonds of similar characteristics.
2. Foreign matter, metallic for HPHT and black strands of unconverted carbon for CVD.
3. Presence of metal impurities for HPHT; nitrogen, silicon and hydrogen for CVD – which allows you to easily identify the synthesized stones by spectrogram.
4. Presence of characteristic fluorescence.

Despite the noted disadvantages, modern high-quality synthetic diamonds are difficult to distinguish from natural ones even by an expert in a jewelry store or pawnshop; only a laboratory can do this. The main disadvantage of artificial diamonds remains their high price, comparable to natural stones of the same quality.

• They are diamonds, have a completely similar structure, and pass any imitation tests;
• Optically they are not inferior to natural stones of the same characteristics;
• Absence of ethical issues associated with child and slave labor in mining;

• High price, comparable to natural diamonds of the same characteristics;
• The number of large stones with high characteristics is very limited.

A very common misconception is that cubic zirconia is a synthetic diamond. This is fundamentally wrong; a synthetic diamond is no different in composition from its natural counterpart, that is, it is a carbon crystal. Cubic zirconia is a cubic crystal of zirconium dioxide, synthesized for the first time by the Lebedev Physical Institute; it is often confused with the natural stone zircon, which, in turn, is a crystal of zirconium silicate. Cubic zirconia has two significant disadvantages:

1. Low hardness, due to which it loses its shine, scratches and chips.
2. The relatively low refractive index is why light can often be seen through cut cubic zirconia, which gives the feeling that you are holding a glass fake in your hands. A well-cut diamond or moissanite does not allow light to pass through, allowing for complete internal reflection of light.

Cubic zirconia is currently a very cheap stone, the market price of which is about $50 per kilogram, i.e. less than half a ruble per carat. Thanks to this fact, cubic zirconia is very beneficial to insert into various jewelry and decorate clothes with it. Some unscrupulous sellers confuse buyers by calling cubic zirconia Brillianite and other misleading names, while unjustifiably raising prices for jewelry with them. Buying gold jewelry with cubic zirconia is not very wise because of the low service life of cubic zirconia, which noticeably fades in 1-2 years due to micro-scratches and abrasions. However, the new well-cut cubic zirconia is quite close to a diamond in its jewelry properties, i.e. capable of delivering impressive sparkle and play.

Nevertheless, cubic zirconia in its sparkle and play compares favorably with Swarovski crystals, which are crystal, i.e. glass with the addition of lead oxide. The addition of lead allows them to achieve some shine and play, but they are very far from being a diamond or even cubic zirconia. Daniel Swarovski’s genius was to put a backing of aluminum foil under a penny crystal rhinestone, which would reflect the light “flowing” through the crystal, making it appear brighter. Neither a diamond, nor, especially, moissanite need such tricks, because. Being well cut, they return all the incoming light back up into the eyes of the observer, giving them outstanding brightness and brilliance.

Products with moissanite American quality

Moissanite has become popular in recent years as a new gemstone that is very similar to diamond. This stone is a silicon carbide crystal first discovered by French chemist Henri Moissan in 1893, which was named after him in 1905. In its natural form, moissanite occurs in very small grains and in meteorite matter. Several years ago, the American company Charles & Colvard patented a method for producing synthetic gem-quality moissanite. Moissanite is most notable for its superior refractive index and dispersion properties to diamond, allowing it to sparkle and sparkle more than diamond. In addition, it is practically not inferior to diamond in hardness, i.e. does not scratch or fade, unlike cubic zirconia.

It is worth noting that two polytypes of silicon carbide crystals are common. One of them (6H-SiC) exhibits yellow fluorescence (glow when exposed to ultraviolet rays), which makes the stone yellowish and cloudy in sunlight. The other one (4H-SiC), which recently went on sale, has no fluorescence and is indistinguishable from diamond in this property. In addition, moissanite has physical properties, such as density and thermal conductivity, very close to diamond, so often even the latest generation portable testers (Presidium Multitester III) mistake high-quality moissanite for a diamond.

In addition to its optical properties, an important advantage of moissanite is its price. With a similar stone size, the price of moissanite will be an order of magnitude lower than both natural and synthetic diamonds. In addition, moissanite can be made to almost any size, unlike synthetic diamonds, the weight of which is currently limited to about 2-3 carats.

We hope that our article will help you make the right choice of stone to set in your jewelry.

• They are not inferior to the best diamonds in terms of optical properties and durability;
• Ideal cut and clarity (for moissanites from the USA);
• Since the end of 2015, colorless moissanites in DF color have been available;
• Indistinguishable from diamond by most tests and instruments;
• The price is significantly lower than diamonds (even synthetic ones);
• Lifetime manufacturer’s warranty.

• The price is significantly more expensive than cubic zirconia;
• Limited number of cuts and sizes available.

We invite you to visit the widest catalog of jewelry with moissanites in Russia on the website of our online store Bright Spark. In our articles you can learn more about the properties of moissanite and a comparative analysis of prices.