Learn about diamonds and how to recognize real diamonds

Jewelry is an exciting and exciting market in many parts of the world. Especially gemstones always have strong attraction for women. Of course, it is indispensable to include diamonds, dubbed the king of precious stones.

At the level of increasingly strong development of science and technology, currently, artificial diamonds (or similar stones) are not only present in laboratories but also overwhelmingly spread throughout the market. jewelry. Artificial stone is increasingly manufactured in the form and quality of natural stone and difficult to distinguish by the naked eye.

Under the name 'artificial diamonds' there are still many different problems. Stones of similar nature are often used by many people based on their shine and equate with diamonds. This article will introduce you to some common types of "artificial diamonds" and some reference tips to distinguish them from natural diamonds.

Real diamonds: Natural diamonds and Diamonds created in the laboratory

Diamonds are one of the two forms of carbon formation with very high hardness (10 on the Mohs hardness scale) and the ability to refract extremely well should be applied in many fields from industry to jewelry. Diamond is said to be a mineral with perfect physical properties and is collected as a rare gemstone.

1 diamond is rated according to 4C quality: Carat (volume), Clarity (transparency), Color (color) and Cut (cut way). Currently only 20% of diamond production in the world is used as jewelry. The rest have poorer qualities used in industry and perform scientific research.

Until the mid-1950s, the only way to be able to own a diamond was to extract it from natural deposits. Unfortunately, diamond formation in nature requires very high temperatures and pressures (about 1200 degrees C and 5 gigapascal). The above conditions are often found at a depth of 140 to 190km under the Earth's crust. That's not to mention the time from 1 to 3.3 billion years to form and only be randomly pushed to the surface by geological forces.

The scarcity of diamond supplies in 1953 led to the creation of synthetic diamonds synthesized by two HPHT methods (high pressure - high heat) and CVD (vapor phase chemical deposition) . HPHT method is responsible for reconstructing deep underground conditions. Meanwhile, CVD method uses chemical evaporation of carbon compounds under the action of Plasma thermal rays to divide gas molecules to create the final product is carbon deposition, thereby developing diamond germ. These two methods are currently widely used to create diamonds in the laboratory.

A diamond test scientist is being built in a microwave reactor

The properties of diamond depend largely on the production process and production purpose. Artificial diamonds are manufactured in laboratories almost similar to natural diamonds. In fact, due to being carefully controlled and carefully done in the laboratory, even artificial diamonds have higher hardness, thermal conductivity, and electrical conductivity than natural diamonds. . Furthermore, diamond manufactured in the laboratory is not contaminated with impurities such as some diamonds extracted from mines.

Therefore, in a sense, both diamond and natural diamonds produced in the laboratory are true diamonds (real diamonds). However, according to experts, the cost of artificial diamonds is very high, because creating a natural-like environment to create diamonds is extremely expensive and more expensive than mining costs. diamonds in nature. Therefore, artificial diamonds are rare in the world jewelry market. The 'diamonds' are often advertised in the market, mostly just synthetic stones, usually Zirconia (CZ stone) or Moissanit.

Diamond impostor - The stones 'seem' like diamonds

Zirconia Stone (Cubic Zirconia - CZ stone) is an artificial crystal made from Zirconium (IV) Oxide which is refined and stabilized at high temperatures. First introduced in 1976, this type of rhinestones is widely available in the market today due to its excellent optical properties, low production costs and low cost.

Unlike natural diamonds or artificial diamonds, hardness CZ stones 8-8.5 on Mohs hardness scale, quickly scratch and color down. Of course, the value of CZ is only a fraction of that of real diamonds in both price and quality.

Moissanite: Although it shines like a real diamond and has almost diamond hardness (9.5 points on the Mohs hardness scale) and has been around for nearly a decade since it was first discovered, it is thought that Moissanite is diamond. But in fact, this is just another mineral completely diamond.

Moissanite was first discovered in 1893 by Henri Moissan. He took his name to name this silicon carbide mineral. This mineral is difficult to form in nature and therefore, Moissanite is almost produced through artificial synthesis. Moissanite was first built in the laboratory by Jöns Jacob Berzelius (who discovered silicon). However, Edward Goodrich Acheson is the official who commercialized Moissanite for use as an iron grinding wheel and cutting tool.

In addition to hardness and refractive properties of light similar to diamond, especially Moissanite has the same thermal conductivity as diamond. Therefore, using a diamond tester based on heat conduction is completely useless for Moissanite. Currently, Moissanite is often used in industry. Although Moissanite is not popular in the jewelry market, but Moissanite is completely worthless compared to real diamonds.

How to distinguish real diamonds from some other stones?

The most accurate and effective way to make sure your diamond is really valuable is to evaluate it through a specialist at reputable and professional assessment centers. Worldwide, the American Gemstone Institute (GIA) and the American Gemstone Association (AGS) are a number of well-known and reputable accrediting organizations that are able to offer standards as well as credible diamond test results. depend.

Currently, a number of quality control centers in Vietnam have diamond assessment services and many other gemstones. Accreditation results will be accompanied by quality certificates.

4C standard

Before the 1950s, there were no professional organizations and unified indicators in the world to assess the value and quality of gems. Evaluation results may vary depending on the assessment. However, the American Gem Institute ended the status of 4C, a popular diamond evaluation standard in the world today.

The 4C standard will score 1 gem based on 4 physical characteristics : color, transparency, cutting and weight (carat).

Color: the color of a diamond is evaluated on a scale from D to Z through comparison with the best quality tablets used for comparison. According to GIA's standards, D-grade diamonds will not have color, transparent as a drop of pure water and of course have a higher value. Conversely, level Z will be tinted yellow or brown. Between the DZ there are still some other levels based on the color of the diamond pattern. In particular, Z-grade diamond has a very rare yellow color and high value.

Transparency: Evaluated based on the results when viewed under a magnifying glass 10 times to check the number of scratches, the color of the fractures, their position, all of which are used to evaluate diamonds. All of these factors affect the transparency and brilliance of the diamond.

How to cut: There are many mathematical studies that are studied to make the amount of light that it reflects the most. One of them is the work of mineral favorite mathematician Marcel Tolkowsky. He was the one who came up with a way to cut the circle and set out the appropriate ratios for it. A modern round diamond cut on the surface has all 57 sides. In particular, the upper part has 33 faces and the lower part has 24 faces. The upper part has the task of scattering light into different colors while the side is responsible for reflecting light. This criterion is evaluated according to 5 levels of light reflectivity, light scattering ability.

Carat mass: of course, the bigger the diamond, the bigger the weight, the higher the value. 1 carat unit is equivalent to 200 mg and can be divided equally into 100 points. 1 point of 1% carat or 2mg is used to evaluate diamonds with a mass of less than 1 carat.

Below is a table of assessment of GIA made diamonds based on the 4C standard. Excluding fake paper making, you can say, if your diamond is certified, you can be assured of the value of the diamond you own.

However, in case you are about to buy a diamond without any certificate. In addition to appraising by professional agencies, you can use some of the following simple testing procedures to distinguish real diamonds from CZ stones.

Look at it. Observe very carefully and subtly

Diamonds have a high refractive index and can bend light through the crystal mesh. Meanwhile, due to structural differences, when light passes through the CZ stone, there will be more prismatic lines.

To verify this, if the stone has not been attached to the jewelry, you can place it on a lettered newspaper (the top of the diamond round must be on the newspaper, not horizontal). If you can read the text below, that stone may be a fake diamond. In fact, in the same experiment, you can't read the text if it's a real diamond due to the high refractive index that will prevent you from looking down.

Similarly, you place the stone above a dot drawn on a white and flat sheet of paper. If you see two refractive images (like the virtual image of a dot) or you see a mirror image inside the stone, it could be Moissanite.

In addition, light reflected from a diamond often exhibits shades of gray. If you see too much light with a color like a rainbow, it may not be a real diamond.

So fake 'so perfect'

As a natural product and does not undergo many quality interventions, natural diamonds are usually light yellow or light brown in color and may include some spots of other minerals commonly called invasive beads. Enter inside the crystal grid structure.

In contrast, CZ stones are created in sterile environments and will be perfect. Of course, this is not the only determinant of determining the problem. Maybe this extremely perfect stone is a diamond manufactured in a laboratory and is more expensive than artificial diamonds?

You can also observe the stone belt (the widest part of the diamond cross-section). If the belt is too smooth and rounded, it could be CZ stone. Diamonds always have flat edges, which can be a lot of aspects that you can feel if you are observant. One never cuts a diamond.

Counterfeit goods are twice as heavy as real goods

In terms of form, it is possible that CZ stones are like diamonds, but they are actually materials with a higher specific gravity. With specific gravity from 5.6 to 6.0N / m ³ , CZ stone is 1.7 times heavier than 1 diamond with the same volume. You can compare the stone with 1 real diamond of the same size as 2 palms, you will get this difference in weight. The heavier ones will be CZ stones.

Diamonds will be attracted to steam

Another test method is to use your breath. If you breath in a real diamond and try to let it cling to the steam, its surface will not be cloudy by the breath. This is because diamonds have a strong thermal conductivity so the steam will dissipate almost immediately. If the steam clings quite a bit on the stone, it is likely to be CZ.

Drop in the water: if the stone sinks down, it's real diamond. The fake stones will float or float in the middle.

Another special feature is that diamonds will not be seen in X-ray films. Meanwhile CZ stones or some other crystals are available. On the other hand, when placed under UV light, many diamonds will glow in blue, some diamonds will not fluoresce even though it is still a real diamond. However, if you put 1 Mossanite under UV light, it will be very light green, yellow or gray.

Some technical measures

Using electric current: The distinction between diamonds and Moissanite by the naked eye is almost impossible. Instead, people use a handheld device that can generate an electric current through a stone to evaluate its electrical conductivity. Based on the difference in electrical conductivity of diamonds and Moissanite, one can quickly distinguish it by this method.

Using heat: Diamonds have very high conductivity and conductivity. To check if the stone is a real diamond, people use a device to transfer heat to the stone. This method can be checked for a maximum of 30 seconds. If the stone drops quickly after being heated, it is likely to be a real diamond.

Take prestigious assessment tests

The above methods are mostly only perceived and give only suggestions. If you want to know the value of a stone, you should still go through rigorous scientific tests with high-precision specialized equipment.