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Is it possible to distinguish cubic zirconia from a diamond by eye?

Diamonds are the most expensive gemstones obtained from the processing of natural diamonds. The main diamond deposits are located in Africa, Russia, Canada, and Australia. The most important jewelry properties of diamonds are luminescence (non-thermal glow) and the ability to dispersion (splitting a light beam into individual colors of the spectrum). No other stone can compare with the play of light, shimmers and flashes of a processed diamond.

Basic characteristics of a diamond

Diamonds are cut diamonds. Their mass is measured in carats, 1 carat = 0,2 g. The cost of 1 carat depends on the quality of the stone and ranges from 50–500 thousand rubles. Small stones weighing up to 0,29 carats usually have a simplified cut of 17 facets; specimens weighing 0,29–0,99 carats have 33 facets. Standard cut: round, with 57 facets. There are 33 faces on the top of the stone and 24 on the bottom. Diamonds, both raw and processed, are highly hard. On the Mohs mineralogical scale, the hardness of natural diamond is 10 out of 10. One of the main properties of diamonds is their clarity (Clarity). Its degree is determined by the number and severity of inclusions and surface stains. The fewer defects, the more expensive the jewelry is. The basis according to which the color of a stone is assessed is colorlessness. The exception is initially colored (fancy) diamonds, which are quite rare.

Origin and properties of cubic zirconia

The name “cubic zirconia” is derived from the abbreviation FIAN – Physical Institute named after P. N. Lebedev RAS. This synthetic stone is a modification of zirconium oxides. Zirconium dioxide is as close in properties as possible to pure carbon, which makes up diamond. Artificial diamonds are produced using Soviet technology not only in Russia, but also in other countries, where they can be called zirconites or jevalites. Cubic zirconias can rival the brilliance of many natural gemstones. They are distinguished by a wide range of colors and affordable prices. The hardness of cubic zirconia is lower than the hardness of a diamond and is equal to 8 points, although the density of an artificial stone is almost three times higher than the density of a natural diamond. Cubic zirconias are used in jewelry and in the production of optical equipment.

Key differences between diamonds and cubic zirconias

Diamonds and cubic zirconia differ from each other in origin and physical properties. In terms of decorative characteristics, artificial imitations are often not inferior to their natural counterparts. Jewelers in budget-class jewelry use cubic zirconia, which is the cheapest imitation diamond. These artificially obtained minerals are very similar in appearance to valuable natural minerals. To avoid becoming a victim of scammers, you need to understand the visual difference between a diamond and cubic zirconia. You can conduct tests using improvised means or special equipment.

How to distinguish a diamond from cubic zirconia at home

The best way to avoid buying a fake is to purchase a diamond or jewelry from a branded store. Unframed stones, diamond rings, earrings, crosses and other jewelry with precious minerals are accompanied by tags and certificates. You can check the authenticity of a stone with high accuracy by contacting a specialist who will conduct tests using special equipment. There are a number of signs by which you can distinguish diamonds from cubic zirconia by eye, at home.

Po certificate

In international practice, diamonds weighing more than 0,5 carats, sold both without a setting and as part of jewelry, are subject to certification. In Russia, a certificate is issued for stones without a frame. Separate certificates are not provided for precious inserts used in jewelry. All information about them is indicated on the tags accompanying the jewelry.

By cut

In the classic version, the diamond has 57 facets (or less), and all of them are sharp. Artificial stones often have more edges and are rounded. The longer the decoration is used, the more clearly the rounding of the edges is visible.

By exposure to heat

Diamond has good thermal conductivity – 900−2300 W/(m K). This is one of the highest rates among solids. If you rub a diamond with warm fingers, the surface will not heat up: the heat will quickly spread throughout the entire volume of the stone. Cubic zirconias heat up easily. You can breathe on the surface – there will be no traces left on the diamond, but the cubic zirconia will fog up.

By cleanliness

Diamonds of “pure water” (transparent, clean, without defects) are rare and expensive. Most often, natural stones contain small inclusions and/or bubbles that are easy to detect by visual inspection. Cubic zirconia, used in making rings, pendants, crosses, earrings and other jewelry, is ideal in shape, clarity and color.

By exposure to light

When the light hits the surface of diamond inserts in earrings, rings, pendants, it refracts, making the jewelry shine like stars. The dispersion of diamonds is much higher than that of cubic zirconia. This is due to the fact that a natural gemstone reflects almost all light rays, while a synthetic mineral partially absorbs them. Natural minerals, when illuminated by ultraviolet rays, give a bluish glow, and cubic zirconias give off shades of grey, pink or green (depending on the impurities added when creating the stones).

According to magnetic properties

In most cases, natural diamonds do not have magnetic properties, but occasionally there are exceptions (if there are large inclusions of magnetite or pyrrhotite). Synthetic specimens are almost always attracted by a magnet.

By weight

The density of cubic zirconia is almost three times higher than that of a diamond. Therefore, by comparing the mass of two specimens of the same size, you can immediately determine which stone is artificial and which is natural.

Is it possible to determine the authenticity of a diamond by mechanical effects?

Testing the strength of a diamond using abrasive materials, such as sandpaper, is not recommended, since light scratches may remain even on a natural stone. When worn carefully, inserts made of cubic zirconia and diamonds retain their original appearance. Leaving your rings on while you clean or apply makeup can damage both natural and synthetic stones. It is almost impossible to determine the origin of a mineral by its resistance to mechanical stress.

Professional ways to verify the authenticity of a diamond

An inexpensive fake can be easily distinguished from natural stone at home: sometimes a visual inspection is enough for this. But cubic zirconias are high-quality artificial crystals that really resemble diamonds. Professional gemologists use different methods to determine authenticity.

Thermal conductivity test

The thermal conductivity of the stone is measured using the Diamond Tester. This device is used by people who often work with jewelry. But inexpensive equipment cannot guarantee one hundred percent results: scammers have learned to fake diamonds. They cover the surface of cubic zirconia with a film of crystallized carbon. This is how you can fool some models of portable testers.

Electrical conductivity test

Many synthetic stones are semiconductors, meaning they conduct electricity. Gemologists have equipment that allows them to evaluate the degree of conductivity and distinguish a natural crystal from an artificial one.

Analysis under a microscope

If a magnifying glass is not enough for a qualitative assessment, gemologists use powerful magnifying devices. They allow you to see the smallest defects, see the sharpness of the edges and the features of the cut. Specialists can use electron microscopes, through which the structure of the crystal is visible. If the stone is synthetic, microscopic clusters of single crystals will appear in the image, as if fused with each other. And if the mineral is natural, all single crystals will be faceted.

Weighing on carat scales

Gemologists have special carat scales on which they can accurately determine the size of the crystal. Cubic zirconia weighs approximately 55% more than diamond.

Other assessment methods

Authenticity is determined by a set of criteria: light absorption, luminescence, photoluminescence and others. Tests carried out on different types of instruments provide error-free results.

Interesting Facts

There is a strong belief that diamonds are invisible in clean, non-chlorinated water. This is wrong. Natural specimens, even colorless ones, can be seen in water, but not too clearly. But if you put cubic zirconia into water, you will be able to clearly see its edges. There are no inserts made of natural diamonds in costume jewelry. If the seller claims that the frame made of medical alloy is a piece of jewelry, this is not true. As a setting for natural stones of the first order, 925 silver, gold of different colors and platinum are used.
How to distinguish a diamond from cubic zirconia How to distinguish a diamond from cubic zirconia Diamonds are the most expensive precious stones obtained by processing natural diamonds. The main diamond deposits are located in Africa, Russia, Canada, and Australia. The most important jewelry properties of shaved. A diamond is a true aristocrat among stones, especially if it is distinguished by high clarity and high-quality cutting. Natural diamonds of pure water are very expensive, and if we are talking about stones of rare shades (for example, blue, green or red), then their price is measured in hundreds of thousands, or even millions of dollars. There are a lot of scammers around diamonds, like other valuables. Royal stones are counterfeited very often, and sometimes you can only determine whether it is a diamond or an imitation in a laboratory. It’s one thing when you consciously buy an analogue of a diamond simply because you can’t afford the original; it’s another thing when they sell you a fake for a significant amount of money, deceiving you in the most unscrupulous way. The topic of our conversation today is how to distinguish a diamond from other stones and other analogues.

Diamonds as they are

Diamonds are cut gem quality diamonds. This means that they are large enough (from 0,1 carats), transparent, have a minimum of flaws and are suitable for cutting, that is, they can be used for the production of jewelry.

During cutting, a diamond loses at least half its weight. There are special programs that allow you to choose the optimal cutting method for a particular specimen.

Chemically, diamonds are pure carbon, that is, they are close relatives of ordinary graphite (as in a simple pencil). However, over millions of years, under favorable conditions, carbon undergoes a magical transformation, turning into a transparent sparkling mineral of wondrous beauty. It is the hardest substance on Earth and is considered the standard on the Mohs scale. Diamond is not such a rare mineral, but gem-quality stones are rare, which determines their fabulous cost. Small and cloudy diamonds are widely used in industry, for example, in the creation of cutting tools. Diamonds are mined on almost all continents except Antarctica. Rich deposits have been discovered in Africa (Botswana, South Africa, Angola), Canada and Russia. At the moment, Russia is the recognized leader in the extraction of gem-quality minerals. Yakut diamonds are famous throughout the world!

The world’s diamond reserves are gradually depleting. Their replenishment is not expected, because the age of natural minerals ranges from 100 million to several billion years!

Diamond analogues

  • Synthetic diamonds. Attempts to create an artificial diamond were made a long time ago, but were crowned with success only in the middle of the last century. The technology for producing jewelry synthetic diamonds is complex and expensive, so at the moment they are only 15-20% cheaper than their natural counterparts.
  • Synthetic minerals. The most popular among the minerals of this group are cubic zirconia and moissanite (the latter are significantly more expensive). Visually, they are very similar to diamonds, quite hard, but they differ in a fundamentally different formula and physical characteristics.
  • Imitations. This group includes both cheap natural minerals (topaz, zircon, rock crystal) and all kinds of rhinestones (including the famous Swarovski crystals).

Natural diamonds are a great investment. There are fewer and fewer of them in nature, and they are constantly rising in price. The cost of synthetic diamonds, on the contrary, is decreasing: technologies are improving and becoming cheaper.

How to distinguish a diamond from cubic zirconia

A diamond differs from a cubic zirconia in its entire essence, expressed in a chemical formula. If the formula of diamond is simply C, that is, carbon, then the formula of cubic zirconia is ZrO2 (zirconium dioxide). They are often called zirconium or zircons, which is incorrect: the first is a metal, the second is a natural semi-precious yellow mineral.

Cubic zirconias are very similar to diamonds, but differ from them in optical properties, have more rounded edges and not so outstanding hardness. They are widely used not only for jewelry purposes, but also replace diamonds in other areas where strength of as much as 10 on the Mohs scale is not needed.

Cubic zirconia is a development of the Soviet Lebedev Physical Institute. Lebedeva, who blew up the jewelry market in the 1970s. But scientists just wanted to get an inexpensive artificial crystal with special properties suitable for creating laser-based equipment!

The cost of cubic zirconia is decreasing day by day, which makes it possible to use it even in costume jewelry. Unfortunately, it is often used to deceive gullible buyers who want to purchase diamond jewelry at a low price.

By experimenting with additives, cubic zirconia of various shades is obtained. We have learned to imitate even the rarest polychrome alexandrite, which costs fabulous money!

The easiest way to distinguish cubic zirconia from a diamond in a ring by eye is to simply breathe on the stone. If it fogs up, then you are guaranteed not to have a diamond.

There are other ways to distinguish these minerals without resorting to laboratory analysis:

  • Fat test. Place a little vegetable oil on the stone. On a diamond the drop will remain intact, on cubic zirconia it will disintegrate.
  • Optical properties. Place the stone on the printed text. If the letters are readable through it, then it is cubic zirconia.
  • Shine. Cubic zirconia shines almost as brightly as diamond, but produces a multi-colored spectrum. The brilliance of the diamond is silvery with yellowness, in monochrome.

Despite the universality and general availability of these verification methods, they are sometimes uninformative for the amateur. Therefore, you should refrain from purchasing expensive jewelry second-hand and from unauthorized retail outlets.

If you consciously buy jewelry with cubic zirconia abroad, then most likely it will have the CZ marking on it. If you are deliberately misled, there will be no identifying marks.

Differences between moissanite and diamond

Let’s consider another analogue of the “king of stones”, moissanite. It is silicon carbide and has the formula SiC.

Natural moissanite was first discovered at the end of the last century in Arizona. Its discoverer was the French chemist Ferdinand Moissan, who christened the new mineral with his own name.

As it turns out, there is very little natural moissanite on Earth: it is found mainly in the remains of meteorites. As a rule, there are small pebbles that do not have a diamond shine and transparency. The largest nuggets found did not exceed a few millimeters in diameter.

Almost at the same time, Edward Atcherson patented a technology for the synthesis of powdered SiC, which was used primarily in the production of abrasives. It was a synthetic carborundum material, chemically a complete analogue of moissanite.

The invention of the technology for synthesizing jewelry-quality carborundum produced a real revolution. Jewelers received an almost complete analogue of a diamond, which is more than an order of magnitude cheaper than its noble counterpart. However, even synthetic moissanite is much more expensive than cubic zirconia.

Natural moissanite is negligible. So don’t trust sellers: you won’t find jewelry with this naturally occurring mineral. But carborundum is a permanent resident of jewelry store shelves.

It is almost impossible to distinguish moissanite from a diamond at home, at least not for a specialist. All methods that can be applied without the use of special equipment lead to damage to moissanite or require the presence of a natural diamond as a sample.

You can recognize a diamond next to a moissanite by its more subdued shine: the second shines brighter due to its higher refractive index. Moissanite is equally transparent, very refractory, and resistant to aggressive chemicals. Its hardness ranges around 9 on the Mohs scale. This means that it can be scratched with a diamond, but not with anything else.

If you don’t mind the stone, you can perform a basic thermal test. Apply the flame of a match or lighter to the diamond and moissanite. Both stones will become smoky, but if the diamond appears in its original form after cleaning the carbon deposits, the carborundum will turn green and become cloudy.

How to distinguish a real diamond from a fake

Almost any piece of glass can be cut like a diamond, but this will not turn it into a noble diamond. However, this is sometimes enough to deceive a gullible buyer, attracted by a very tempting price.

A diamond weighing 0,25 carats costs at least 60 thousand rubles. A half-carat diamond is valued at three times more expensive. And if we are talking about flawless and larger specimens, the price jumps by an order of magnitude or more!

There are many ways to distinguish a diamond from glass or other types of fakes. The rougher the imitation, the sooner inconsistencies are identified. So grab your magnifying glass and take a look at:

  • Cut. The diamond has perfectly smooth, clear edges, without rounding or the effect of double rays. Between the lower and upper parts of the diamond (“pavilion” and “crown”) there is a kind of girdle, a girdle. It should be slightly rough to the touch.
  • Flaws. Yes, the fewer flaws a stone has, the higher it is valued, but nature does not tolerate faceless perfection. A natural diamond will definitely show some flaws (turbidity, dots), while an artificial crystal will be perfect.
  • Scratches. As mentioned above, diamond is the hardest substance on Earth. A priori, it cannot have micro-scratches or other damage. The glass can be scratched instantly, even with a nail file. This test is not indicative only for moissanite.
  • Transparency. A diamond is transparent, but due to its high refractive index, you will not be able to see anything through the stone – you will only see a shining point. You can even read through cubic zirconia and glass.
  • Range. A diamond scatters rays in a white or slightly yellowish spectrum. Each face casts only one ray. Most diamonds exhibit a bluish glow when exposed to ultraviolet light. But there are also exceptions.
  • Frame. Diamonds set in silver, and even more so, jewelry alloys, are nonsense. Only gold of at least 585 standard or platinum!
  • Fastening. No jeweler would use a setting to hide the “pavilion” ring, that is, the lower part of a large diamond. Cubic zirconias and glass usually bashfully hide their rears. They are often attached with glue, which is unacceptable for diamonds.

It is impossible to distinguish a natural diamond from an artificial one at home! Artificial diamonds (not imitations, but complete analogues) have the same elemental composition, chemical and physical properties as natural ones.

You can distinguish a diamond from glass by resorting to the simplest tests, many of which were mentioned in the appendix to cubic zirconia. This is, first of all, a fogging test: the surface of the diamond does not fog up or traces of breath evaporate in the blink of an eye.

The “drop” test is also indicative: a drop of oil or water on the surface of the diamond does not spread. In addition, a diamond remains cool for a long time even when squeezed in the hand, while fakes immediately take on the temperature of the human body.

A little about certification

There are many ways available to check whether the diamond you are looking at is real or imitation, but none of them can give an absolute guarantee. Even experts can only distinguish cheap fakes at first glance, in other cases using laboratory research methods.

The authenticity of the stone is established after a series of tests carried out in accordance with the protocol. The optical characteristics of the stone are checked and it is carefully examined in various lighting conditions and environments using electronic equipment.

Each natural diamond receives a certificate indicating its characteristics. The most authoritative are the GIA certificates issued by the Gemological Institute of America. HDR and AGS certificates are highly rated.

Private companies often offer certification services at a more affordable price than the above organizations, but you should not always trust them. It is unlikely that they will award a certificate of authenticity to an outright fake, but they can easily “play” with the characteristics of the stone.

Russia has its own certification system and institutions that evaluate precious stones. Certificates are issued in Russian and contain a “portrait” of the stone, as well as information about its characteristics and personal number.

Russian legislation requires mandatory indication of the characteristics of the stone insert when selling jewelry. So if you buy jewelry in a store, you can determine from the tag what your diamond can “boast” of.

No non-specialist can determine the origin of a stone with absolute accuracy, and, unfortunately, forgery of certificates is not uncommon. So if you can afford high-end jewelry, do not buy it from dubious places. Diamonds and savings are incompatible concepts!

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