Therapeutic properties

How to check whether a diamond is real or not?

Diamonds have remained the most popular precious stones for many centuries. They are given as gifts, passed on by inheritance, kept as a family heirloom, but they are always admired for the grace and severity of their clear edges. A diamond becomes a luxurious and beautiful diamond after the master cuts, polishes and polishes the mineral. Real diamond You can check whether the diamond in front of you is real by its unique properties, including:

  • hardness. A diamond cannot be scratched; only another diamond or diamond can leave a mark on it;
  • high refractive index and strong dispersion. As soon as light hits a well-cut real diamond, the gemstone begins to “play”, flashing with multi-colored lights. All light falling on it from all sides is reflected inside and exits through the top edge;
  • fragility. If you hit a diamond hard with a hammer, it will crack;
  • does not change color or fade. Even after hundreds of years, the diamond will still sparkle beautifully in the light.

Differences between a diamond and a fake

To choose a diamond, it is important to evaluate its main characteristics. Most gemological laboratories that evaluate the value of diamonds use the GIA international classification, also called 4C. The grading system includes four important characteristics that determine the quality and cost of precious stones: carat, cut, color, clarity.

  • Carat, that is, mass. 1 carat is equal to 0,2 grams. A diamond is considered large if its weight exceeds 1 carat. An average diamond weighs approximately 0,3–0,99 carats, while a small diamond weighs up to 0,29 carats.
  • Color, or color. The most expensive diamonds are completely colorless (if we are not talking about clearly expressed fancy colors). They are rarely found in nature.
  • Clarity, or cleanliness. The brilliance of a diamond depends on how many internal and surface defects it contains. Accordingly, the more transparent the gemstone, the higher its value.
  • Cut, or qualitycutting. A diamond becomes a diamond only after skilful and professional cutting. The precise geometry of the lines, correct proportions and quality of polishing guarantee maximum brilliance and play of light, therefore high quality cutting is an integral characteristic of an expensive gemstone.

A diamond is a unique gemstone. It is not surprising that the market offers imitations that are more or less similar to it, from rock crystal and rhinestones to carbon crystals synthesized in the laboratory.

For example, used in jewelry rhinestones made of lead glass with a high refractive index and dispersion. They sparkle quite brightly, but it’s just glass and nothing else.

Rhinestone – natural stone, natural silicon dioxide, one of the most common minerals. Both jewelry and souvenirs are made from it. Rock crystal, unlike a real diamond, has soft, “smoothed” corners. In a cut diamond they are clear and sharply defined. If you compare the shine and play of light of a gemstone and rock crystal, then crystal definitely loses. No other mineral can compare with the beauty of a diamond.

Фianite – a man-made crystal, zirconium dioxide with a cubic crystal lattice. It was synthesized in 1970 at the Physical Institute of the USSR Academy of Sciences (FIAN), where it got its name. Colorless and transparent, it is less hard and lacks the inherent shine of a natural diamond, and experts recognize it quickly and easily, even without sophisticated equipment.

Moissanite – silicon carbide. In nature, this mineral is rarely found in the form of small crystals that have no decorative or industrial value. The synthesis of this solid and refractory compound for technical needs began at the end of the 19th century, and in the 20th century technologies for growing artificial transparent single crystals of jewelry quality appeared. They are used in jewelry. Moissanite is slightly inferior in hardness to natural diamond and has high thermal conductivity and light refraction, so it is more difficult to distinguish it from a real diamond than, for example, cubic zirconia.

A synthetic (artificial, laboratory-grown) diamond, or, as it is called in English, LGD – lab-grown diamond – a crystal with physical and chemical properties identical to natural ones. Not so long ago, the creation of artificial diamonds was so expensive that their creation was of purely scientific interest. But as technology developed, the cost of growing them decreased. And, although this still requires a colossal amount of energy, today such carbon crystals can be synthesized almost unlimitedly – unlike natural diamonds, the deposits of which are gradually depleted. Therefore, “synthetics” do not have the value of a natural diamond – just like the most accurate reproduction of a painting by a great artist will never be comparable in value to the original. So, artificial diamonds and jewelry with them, unlike rare natural ones, do not have investment potential. What can we say about the emotional component – it is unlikely that an artificial stone, no matter how beautifully it plays in the light and cuts glass, will warm the soul.

A real diamond shines in the light

Since it is very difficult even for an expert to distinguish a man-made diamond from a natural one, to be sure of the origin of the diamond, it is better to first choose a trusted jewelry seller. One that can not only confirm their authenticity, but also guarantee “pedigree” with its reputation. For example, ALROSA Diamonds diamonds are accompanied by electronic passports, which indicate both the region where the diamond was mined and the place where it was cut.

The difference between a diamond

By purchasing diamonds from world-famous companies such as ALROSA Diamonds, you receive products of guaranteed high quality, confirmed by all the necessary gemological reports. The main thing is to make a choice. After all, each of these pieces of jewelry is beautiful, impressive and very similar to the jewelry of your dreams.

Unlike a diamond that plays with its facets, a natural diamond does not look as presentable. The jeweler receives a nondescript-looking sample with an irregular shape for processing. The mineral is dull, its surface is covered with a kind of “crust”, riddled with cracks. But even in this state, the diamond is already able to reflect light and play with its edges. The jeweler’s task is to cut the stone so that its individual features in the form of voids and cracks become its additional advantages. A diamond in its natural form will be of interest to collectors and people who want to receive an exclusively cut diamond. For an ordinary person, it is possible to purchase a diamond when traveling on “diamond tours”, where stones are purchased directly at mining sites. In order to avoid becoming a victim of deception or to correctly evaluate a specimen that has fallen into your hands, it is worth understanding the signs of a genuine diamond.

Characteristics of the stone

  • The chemical formula of diamond is C (carbon).
  • The variance is 0,63.
  • The refraction of a shining crystal is 2,4175, the indicator can change upward due to the inclusion of impurities.
  • Hardness on the Mohs scale is 10 units.
  • Specific gravity – 3,48-3,55 g/cm3.
  • The mineral is resistant to acids and alkalis.

Types and differences of analogues

Due to the high cost of diamonds, jewelers and manufacturers of electronics and equipment are looking for ways to reduce production costs without sacrificing quality. This is how diamond analogues appeared, making it possible to imitate the shine, hardness and aesthetic component of natural stone.

  • Moissanite is a silicon carbide. In terms of its ability to sparkle, moissanite is even 25% ahead of diamond. The stone also refracts colors perfectly and has similar thermal conductivity. Moissanite is inferior only in hardness – 9,25 on the Mohs scale.
  • Cubic zirconia or cubic zirconium. Its low cost made it an ideal option for inexpensive jewelry products. The characteristics are significantly inferior to diamond and moissanite.

Also, rhinestones (the cheapest glass option), colorless sapphires, rutile, fabulite, yttrium-aluminum garnet, gallium-gadolinium garnet, zircon, and scheelite can be used as substitutes.

In most cases, the desire to confirm the authenticity of a stone applies to diamonds. When purchasing a product or inheriting jewelry, you want to understand how valuable the purchase is. A diamond is a cut diamond, their properties will be identical, except for trying to see the text through the stone. The cut will prevent you from seeing anything through the stone due to the refraction of light within. Other verification methods are suitable in both cases.

Ways to check

Not only diamond is colorless and transparent. There are other stones with similar characteristics. To understand that what you have in front of you is a specimen of a diamond, you can use both everyday verification methods and expert evaluation options. The ideal option is a comparison with a standard, but either jewelers and collectors or gemological laboratories can afford this. In other cases, it is worth relying on knowledge about the qualities of diamond and its physical and chemical properties. Visual inspection and hardware testing in the laboratory are also possible.

Natural qualities

Diamond has a unique intensity of shine; it sparkles brightly, regardless of the type of light source. The stone has ideal transparency, but to come across an absolutely colorless mineral is a great success.

The shade of a diamond depends on the concentration of impurities, inclusions, as well as the intensity of exposure to radiation. One stone can have several shades at once. Most often in nature, stones of white and yellowish colors are found.

Gray milky and black color is a sign of a technical diamond. The board, ballas and carbonado units are also painted. Of all mined diamonds, aggregates account for 80% of the total volume.

It is impossible to find two identical diamond samples in nature; stones are as unique as fingerprints.


Diamond has the highest rating on the Mohs scale. This is the hardest material. Diamond has the highest abrasion resistance. This is the reason for testing the stone with sharp objects and abrasives. A diamond can only be scratched with the same stone. Natural diamond can cut glass.

But the proposal to hit the diamond with a heavy hand may turn out to be dubious. In different directions of the crystal, its hardness varies. If you hit it too hard, the diamond will split along planes parallel to the edges of a regular octahedron. The technology of cutting, grinding and cutting rough diamonds is based on this property.

If you do not plan to cut the fragments in the future, it is better to move the hammer away from the stone.

Thermal conductivity

A diamond can be verified for authenticity by its characteristic feature of thermal conductivity. It is suggested to breathe on the sample: if the stone is real, then there will be no condensation from breathing on it. Also, it will take a long time to warm a diamond in your hands. It is worth remembering that you can only distinguish a diamond from a glass fake or a synthetic analogue. If you hold a natural gem with a colorless color, it may have characteristics similar to a diamond.

The thermal conductivity of diamond is 0,9-2,3 kW/(m*K), this is the highest among known solids. That is why it is used as a semiconductor. The efficiency threshold of silicon analogues cannot exceed 100 o C.

Due to the high thermal conductivity of diamond, for example, weapons cool quickly. The thermal conductivity of diamond [0 35 cal / (cm-sec – C)] is higher than the thermal conductivity of hard alloys [0 05 – 0 19 cal / (cm-sec – C) 1 and high-speed steel [0 05 – 0 07 cal / (cm-sec — C) 1. This property allows heat to be removed from the cutter in a diamond tool faster than in a carbide tool.

Fat absorption

This property of diamonds is used, among other things, when raw materials are supplied for processing. Diamonds stick if you first drop regular vegetable oil on them and then press them to the surface of the glass. Counterfeits and other minerals do not react this way, so the method is considered 100%.

Another option for checking the authenticity of a stone is to use a felt-tip pen with thick ink. If you draw a line across the surface of a fake, the ink will fall out in drops, but on a real diamond the line will be smooth.

Interaction with different environments

A diamond is visible in water, it will not disappear. The density of water is less than that of a diamond; the refractive index of light will also be inferior to a gem.

  • Density: 0,10 g/cm³ for water versus 3,47 – 3,55 g/cm³ for diamond.
  • Light refractive index: 1,33(H2O) and 2,42 (diamond).

Based on the numbers, it can be seen that hiding a stone in a bottle or glass of water will be problematic in reality. But water can establish the authenticity of a stone. If you drop water on it and try to puncture the drop, it will remain intact, but with fakes it will spread.

Dust will also help to reveal a fake diamond. If you place a stone near small particles, the dust will be attracted to the fake, but the real diamond will remain clean.

Under the influence of high temperatures of 800-1000 o C, diamond can return to the graphite state. That is why they must be stored in a fireproof safe or in a safe deposit box. Vacuum storage will help increase the critical interval to 2000 o C.

Diamond is inert towards solutions of acids and alkalis, but is quite easily etched at 600-800°C in molten alkalis, salts of oxygen acids and metals. But if you put a fake in hydrochloric acid, it can change color, turn brown or dissolve.

If you run aluminum over a ground sample, a “graphite” trace will remain on the diamond. Important: such a mark is difficult to remove later, so it is better to experiment on an inconspicuous area.


If it is not possible to obtain the opinion of an expert gemologist, then it is worth using a magnifying glass with X10 magnification or a microscope. It is ideal if you have a guaranteed genuine diamond as a standard for comparison.

  1. Natural stone will always have small defects – cracks, inclusions. Flawless stones are very expensive. In a diamond with an average or “democratic” price, the absence of “imperfections” should be alarming.
  2. Diamond’s ability to reflect light and sparkle is present even in rough stones. A true diamond, when processed, sparkles on all sides, not just on the edges.
  3. Clear and even edges are another visual sign of a genuine stone. Even if it was worn for a very long time, the edges will not be erased. The girdle of the diamond is rough and matte, the smooth and transparent girdle is the privilege of the “glasses”.

To check the quality of a stone “by eye” requires good practical experience. If you don’t have one, it’s wise to enlist the help of a professional appraiser or jeweler who is not an interested party.

Using instruments

Electronic diamond testers are used to determine the authenticity of diamonds. These are devices that focus on the thermal conductivity and reflective properties of stone. It is noteworthy that such a tester will identify a true diamond not only among glass imitations. Natural stone can be found even among artificial analogues.

If the tester model relies only on the thermal conductivity indicator, then it is possible to “deceive” it. Artificial mussanite will have the same value as the original. Will give double hardness. On the Moss scale, moussanite is inferior to diamond in hardness by 0,75 points.

A tester based on light refraction will help you weed out even high-quality imitations. Mussanite will have higher values ​​than diamond. However, such testers have a weak side – they only work with cut stones.

The best option is combined testers. The American brand “Gemoro” is popular among both individual entrepreneurs and owners of jewelry chains. Its cost is about 7000 rubles. There are also Chinese pocket analogs – their cost is 10 times less, they are bought by private individuals. Purchasing a diamond tester is important for those who regularly purchase jewelry, including from collectors and individuals.

You can also check the authenticity of a diamond using laboratory instruments:

  • Under X-ray radiation, the diamond will glow a rich green color;
  • UV light (quartz lamp) will cause the diamond to glow yellowish, violet, pink and blue.

You will not see white reflections in the case of a genuine stone.

It is important to remember that radioactive plating can be used to give a diamond a fancy coloring. At the same time, it is impossible to determine whether the stone was “ennobled” outside a gemological laboratory.

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