History of use

What shines brighter: cubic zirconia or diamond?

On the shelves of jewelry chains, beautiful jewelry shimmers with diamond sparkles on the facets of precious stones. Or are these not diamonds, but cubic zirconias? How to distinguish a natural stone from an artificial one if you are not a professional jeweler or gemologist? A diamond is a desirable acquisition for most women. Received as a gift, it symbolizes the special disposition of the donor towards the recipient. What if the stones were inherited and you need to determine the real value of the property received? During her lifetime, my grandmother claimed that the set was made of diamonds, but what really happened? Are the contents of the box real – a fabulous fortune? Or is it a brilliant fiction, well stylized as a work of art? To answer the main question – “How to distinguish a diamond from cubic zirconia?” you need to understand the nature of both types of stones. There are also proven ways to evaluate the characteristics of stones without resorting to the services of a gemological laboratory.

What is a diamond

This stone is nothing more than a diamond mined from a kimberlite pipe. It was extracted from the rock, washed and cut. Diamonds can be technical and jewelry. When sorting, stones with the best characteristics are selected – according to size, transparency, shade, shape, and the presence of defects due to scratches and inclusions. There are very few perfectly pure diamonds, transparent as if spring water – which is why such stones are very highly valued. More often, inclusions or impurities of other minerals may be found inside the stone, adjacent to the diamonds inside the volcanic rock. Beautifully cut diamonds with fantasy colors are also highly prized. An ordinary diamond is characterized by light shades of blue or green, from light yellow to brown, and there are even black ones. But reddish, bright blue, emerald green or purple are rare. If a stone, in addition to its unique color, has impressive dimensions and is skillfully cut, it is considered a work of art. The diamond often became an adornment of the royal treasury.

What is cubic zirconia

This stone is of synthetic origin, which saw the light of day thanks to scientists from the Lebedev Physical Institute of the Academy of Sciences, or FIAN for short. It is noteworthy that physicists, during experiments, tried to create a substance for use in laser equipment. Certain optical properties of the material were needed. However, cubic zirconia has become a real sensation for the jewelry industry. A synthetic stone allows you to imitate almost any gemstone, while its price in comparison with a diamond is extremely low. Cubic zirconia has made it possible to fill the market with inexpensive jewelry. It is also used in dentistry, the chemical industry, and in the production of optical devices.

Physico-chemical characteristics of diamond, cubic zirconia

  • The hardness of diamond on the Mohs scale is 10, which is the highest level. You can only scratch a diamond with another diamond, and the stone is very fragile and easy to break. Moreover, the splits occur in strictly defined planes – this property is used during the initial processing of stones.
  • Diamond is flammable; it will not withstand even the sun’s rays passing through a magnifying glass. When heated, carbon dioxide is released. In case of fire, high temperature and lack of oxygen will turn diamonds into graphite.
  • Diamonds, a cubic allotrope of carbon, are resistant to alkalis and acids, they are natural dielectrics, that is, they do not transmit electricity.

Cubic zirconia is a chemical composition of cubic zirconium dioxide. Cubic zirconia has a diamond-like luster, which can even exceed the brightness of natural stones. However, in terms of hardness, cubic zirconias are inferior to diamonds – 7,5 – 8,5 on the Mohs scale. In addition, cubic zirconias have more weight compared to natural and synthetic diamonds.

How to distinguish a diamond from cubic zirconia at home

Now let’s move on to the practical part of the question: how to distinguish a precious stone from an artificial cubic zirconia without special equipment? First of all, such knowledge will help you to really evaluate the jewelry that you have got into your hands if you suspect that they are trying to foist a fake on you under the guise of jewelry with a diamond.


One of the most accessible ways to determine what you are holding in your hands. The peculiarity of the diamond cut is that the stone refracts and reflects the light falling on it as much as possible. Thanks to this, the diamond plays beautifully with reflections on its edges, but it is impossible to see anything through it. Also, you will not be able to see other objects through a cut diamond if you look through it into the light.

Cubic zirconia allows you to examine the letters of printed text, as well as objects. It is transparency and the absence of specific refraction of light inside the stone that distinguishes it from a natural cut diamond.

Glitter and Shine

If you bring the stones to a source of bright light and, turning, make the light play on the edges, then a cold silvery sparkle will become a sign of a diamond. But cubic zirconia will play with different colors. However, a lot depends on the quality of the stone and the cut. Professionals do not recommend relying on this method, since the likelihood of error is very high. Even when you compare cubic zirconia to a real diamond, comparing the stones to each other, the brilliance and sparkle of the samples can mislead you.

Test breath

Remember the action typical of treasure hunters – breathing on a stone? So, this is not only to “clean” the find on the sleeve. A diamond, as well as an uncut diamond, will give itself away by not fogging up. It will remain clean and transparent. But on cubic zirconia, warm breath causes condensation to form, which will cause the surface of the stone to become cloudy.

Optics to the rescue

To visually assess the quality of the stone, magnifying glasses with 10x magnification are used. Jewelers also have special microscopes to evaluate the quality of gemstones. Make sure there is bright lighting before examining the sample.

Your task is to evaluate the quality of the glow from one face. For a natural diamond, the glow will be a single line, clear, but for cubic zirconia it will be double – the so-called double refraction means that one ray will go straight, and another will deviate to the side.

Looking for defects

If you do not have access to closed diamond auctions, where stones with impeccable clarity are offered for millions of dollars, then it will become a rule for you that “a defect is a sign of authenticity.” For assessment, it is recommended to take an X20 magnifying glass. Natural diamonds and diamonds sold in jewelry chains will have inclusions and cracks. This will be an indication that the stone was adjacent to other minerals within the rock. Yes, during cutting they try to eliminate flaws or make them invisible, but in most cases they are present in samples with a “decent price”. On the contrary, impeccable quality, transparency and absence of flaws at a reasonable price for jewelry are a sure sign of the use of artificial stone.

Sharpness of edges

This method can be practiced by people who have experience with real diamonds – they not only saw them, but had the opportunity to comprehensively study, remember the characteristic features and sensations of the stone.

  • The diamond has characteristic sharp edges that cannot be obtained with artificial cubic zirconia. In the second case, the edges of the faces are always slightly more rounded.
  • Another sign of a diamond’s authenticity is the presence of smoothness flaws. Cubic zirconia will be flawless on planes.

A person who does not have experience interacting with real diamonds will not be able to discern this difference. This skill is possible for practicing jewelers and professional appraisers.


Knowledge about the thermal conductivity of diamond and cubic zirconia will also help identify a natural stone. To experiment, just warm your hands and take the jewelry with the stone in your fist. If it took 3-4 seconds to heat the stone, you have cubic zirconia. A diamond will remain cold comparatively longer due to its thermal conductivity properties – it quickly removes heat.


A diamond has a unique hardness – it can only be scratched by another diamond. The stone can withstand pressure of several tons, but it does not have impact resistance – a fragile diamond will crack if dropped or hit by a heavy object. It is believed that sellers will not allow the stone to be scratched if the product has a cubic zirconia insert. However, there is more effective evidence – expert opinion.

Availability of a certificate of authenticity

Retail jewelry chains can sell unmounted stones only if they have a certificate for each sample. The research is carried out in specialized gemological laboratories, where experts evaluate each sample, comparing it with the standard. The GIA, or Gemological Institute of America, certification is trusted throughout the world. Certification of one carat stone will cost $105. In Russia, the leading expert in the evaluation of precious stones is the Gemological Center of Moscow State University.

How to distinguish using fat

There is another way to check the authenticity of a stone, which is used even at the stage of sorting raw materials after washing the diamond rock. Vegetable fat. A drop is enough for the diamond to effortlessly stick to the glass surface. Cubic zirconia will not hold up during such manipulations – it will fall off. Also, on the surface of the diamond, the oil drop will remain intact, but on the surface of the cubic zirconia it will disintegrate.

As can be seen from our list, the most effective ways to distinguish a diamond from cubic zirconia are based on knowledge of the physical properties of the stones. Aesthetic evaluation requires extensive practical experience.

In this article we will figure out which stone in an engagement ring will please the bride most

diamond or cubic zirconia – which is better?

Analogs make jewelry more affordable. The most famous of them is cubic zirconia. It is practically indistinguishable from a cut diamond. Cubic zirconias are of higher quality compared to rhinestones and Swarovski crystals, and therefore are ready to act as an inexpensive analogue of diamonds.


Diamonds have been in great demand among fashionistas all over the world for many years. However, cheap fakes are often given out under the guise of an expensive precious mineral. That is why it is so important to know how a diamond differs from other stones, what characteristics and properties it is endowed with.

  1. Bright shine. It is necessary to look through the stone: diamond has a high degree of refraction, which is what gives rise to such a dazzling shine. No other mineral will sparkle as much as diamond due to its lower degree of refraction.
  2. Transparency. If the diamond is uncut, you can determine its authenticity by the degree of transparency using the following method: place the mineral with its flat surface on a magazine or newspaper. A real diamond is opaque, so it is impossible to see the drawings through it, much less read the text, which cannot be said about fakes.
  3. Invisibility of the cut. When examining a diamond in a setting, the corners and top of the cut should not be visible through it.
  4. Reflections of gray shades. High-quality diamonds may have an additional tint; only minerals with a gray sheen are highly valued. If the stone sparkles with all the colors of the rainbow, most likely you are looking at a poor quality diamond or a fake.
  5. Doesn’t fog up. To verify the authenticity of a diamond, you can breathe on it. If the stone fogs up in a few seconds, you are being offered a fake; a real diamond will remain clean and transparent.
  6. Invisibility in water. This method can only be used at home; it will not help when purchasing jewelry or a precious mineral. If a real mineral is placed in a glass of clean water, it will remain invisible. This type of fake is known when the upper part of the stone is a real diamond, and the lower part is made of a fake. In the water you will be able to see whether the stone is solid, and you will also be able to see where the genuine and fake material meet.
  7. The weight. As a rule, all other stones are slightly heavier than diamond. For example, the weight of zirconium exceeds the weight of a diamond by 55%. To determine the authenticity of a mineral based on this criterion, jewelers recommend weighing it and checking it against a table that corresponds to the size of the stone in grams or carats.
  8. Stamp A cheap frame may indicate that the stone is fake. You can check the presence of a mark on the frame and verify its compliance with high-quality metal
  9. Ultraviolet testing. The stone should be placed under ultraviolet light; the majority of diamonds glow blue when exposed to ultraviolet radiation. If under the lamp the stone glows yellow, green or gray, it means that you have cubic zirconia in front of you.
  10. Doesn’t heat up quickly. A distinctive feature of a real diamond is that it heats up very slowly and weakly in the hand. If you hold it in your palm, it will remain cool for a long time.


Cubic zirconia is a wonderful jewelry stone that has undoubted advantages of both price and aesthetic nature. Cubic zirconia is an artificial material whose degree of refraction is very close to that of diamonds. It is because of this property that cubic zirconia is often confused with diamonds. There are several ways to distinguish cubic zirconia from a diamond so as not to become a victim of deception when buying jewelry:

  1. You should look through the stone. It will be impossible to see light through a diamond; only a luminous point is formed, while cubic zirconia transmits light very well.
  2. The second difference between cubic zirconia and diamond is the ability to heat up and transfer heat. A real diamond always maintains a low temperature, even in the heat it will be a little cool, and cubic zirconia takes on the ambient temperature.
  3. Another easy way to distinguish a genuine diamond from cubic zirconia is to breathe on the stone for a few minutes. If the stone fogs up, it means it is cubic zirconia.
  4. The hardness of cubic zirconia is at least 15% lower than the hardness of diamond

Expensive diamonds are often replaced by scammers with cheaper versions of stones, including zirconium. The following expert advice on how to distinguish a diamond from zirconium will prevent you from becoming a victim of scammers:

  1. If you are not afraid of spoiling an unnatural stone that was sold to you under the guise of a diamond, dip it in a solution of hydrochloric acid. A real diamond will not be damaged, it will remain just as attractive, and the zirconium will be covered with opaque white spots.
  2. A real diamond after jewelry processing is characterized by its colorlessness and transparency, zirconium is distinguished by the presence of colored impurities.
  3. The stone can be lowered into water: a genuine diamond will sink to the bottom and will sparkle in it, but at the same time it will be almost invisible. Zirconium can be clearly seen in water, but it will not emit a dazzling shine.
  4. If you examine zirconium under a magnifying glass, the stone will show bifurcated back edges.
  5. You can find out about a fake even if the stone is set into a ring. To do this, you need to put it on your finger and look carefully inside: due to total reflection, it will be impossible to see your finger through a real diamond, but through zirconium it will be visible, since this stone has a completely different refractive index.

It’s difficult to say which is better, natural stone or its high-quality analogue. If we are talking about a gift, then it is still more pleasant to accept jewelry with a diamond. If the decoration can be classified more as costume jewelry, then cubic zirconia is perfect. And of course, you shouldn’t be foolish: if you received a ring with cubic zirconia as a gift, that’s the attitude towards you, you shouldn’t rejoice at this gift like a diamond. Although love and attention are more expensive than all jewelry, sometimes a woman wants to have something that has not a relative, but a completely objective value. One way or another, you can purchase jewelry in the catalog of jewelry stores in Stavropol

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