Before we find out how to identify a real diamond, let’s learn a little more about this special stone. The word diamond comes from the Greek adamas, meaning “indestructible”, and the first versions were formed over 2.5 billion years ago.

Sought after by many, it is one of the world’s most famous gemstones. Generally speaking, it’s a type of crystal that belongs to the category of native minerals.

This material is made up of pure carbon, but in crystallised form. In fact, it is the most solid material on the planet and one of the most expensive stones in existence.

Rough diamonds can be found in mines. However, when they are extracted, they tend to have a different shape to what we find in jewellery shops – in other words, they are opaque. The brilliance comes after cutting.

Today diamonds are made in laboratories. Contrary to popular belief, they’re not made up of modified pieces, but have the same chemical composition as those found in nature.

Characteristics of real diamonds

• In nature, diamonds can form in a variety of ways. However, for this to happen, the environment must have extremely high pressures and temperatures. The most common way is in the terrestrial mantle, which is 150 kilometres underground;

• Its structure consists of pure carbon atoms distributed around its vertices, with only one in the centre. This makes the stone compact and of high density (3.5g/cm3);

• The diamond has a high hardness. According to the Mohs scale, the stone has a hardness of 10 – the maximum value that can be measured;

• It is a stone that cannot be scratched by another stone, let alone by different materials. Only a genuine diamond can scratch another;

• Diamonds have a high index of refraction. Therefore, after cutting, it is possible to obtain an extremely brilliant piece.

Como identificar um diamante

How to identify a genuine diamond

But how can you identify a genuine diamond? This precaution is essential, especially as the number of fake gems is increasing.

And you don’t want to take the risk of making a mistake, do you?

With the guarantee that you’re buying a genuine diamond, you’re holding in your hands a valuable piece of jewellery, made from the best materials on the market, that can last for many, many years and even become part of your family history.

The good news is that there are different methods that can be followed by those who wish to learn how to identify a genuine diamond. We’ve put together this step-by-step guide to help you:

1. Use the sniffing technique

A very simple trick to understand how to identify a genuine diamond is the sniffing technique. It works like this: you put the diamond in front of your mouth and release the air. The process is the same as we do with a mirror or glass when we want to write something on its surface.

If the stone remains blurred for more than two seconds, the chances of it being a fake are high. A genuine diamond is known for its ability to dissipate heat quickly, preventing the blurring effect for a long time.

2. Consider the metal that accompanies the jewellery

It’s unlikely that you’ll find diamond jewellery set with an inferior metal such as stainless steel. That’s why you should always consider the material in which the gemstone is set.

The tip is to look inside the jewel and identify the carat of the metal. Precious options usually have the following initials:

• 10K;
• 14K;
• 18K;
• 585;
• 750;
• 900;
• 950;
• PT;
• Plat

On the other hand, if you find the initials C.Z, for cubic zirconia, it is very likely that the diamond is not genuine.

3. Keeping an eye on the sparkle

A true diamond has greyish reflections – never coloured (even coloured diamonds). With this in mind, if the stone is analysed and shows reflections in different colours, it’s best to pay attention.

Don’t forget that genuine gemstones have a high degree of refraction. This means that in front of a good light source, they will reflect an intense and unique glow on each side of your gemstone.

4. Go to a jeweller

Finally, the most effective way to identify a genuine diamond is to take it to a jeweller. Using special instruments, this professional will be able to detect the imperfections that only a real stone has. Fakes, on the other hand, are usually very well finished, with minimal imperfections.

It is worth noting that these imperfections come from the natural mining process – technically known as inclusions. By observing them with a special tool, the watchmaker will be able to tell if the material has stains or slight colour variations.

What types of diamond are there?

To know how to identify a real diamond, you need to remember that there are different colours of this precious stone in nature. Most commonly, they come in translucent, almost colourless yellow and white versions.

However, the Gemological Institute of America (GIA) has also set certain standards for classifying this material and its shades. The classification starts with the letter D, which stands for colourless, up to Z, which refers to models with a striking colour.

Technical information about gemstones is always important for jewellery designers, which is why this article provides information about the 4Cs of diamonds.

The 4 basic diamond classifications

The diamond has 4 basic characteristics.

More than an investment, a diamond is an expression of affection and love; its purchase should be a safe and pleasant experience.

With this in mind, the GIA (Gemological Institute of America) has developed a diamond grading standard that is the most widely accepted in the world and has changed the way diamonds are marketed.

This system, known as “The 4 Cs”, is based on classifying diamonds according to the 4 basic diamond characteristics.

The 4 basic diamond characteristics “The 4 Cs”: are

1. Carat (the weight in carats)
2. Hue
3. Clarity (its degree of purity)
4. Cut (its shape)

Knowing the 4 Cs will help you make a confident purchase based on accurate information and will make it easier to compare diamonds offered by different suppliers.

1. First C – Carat (weight)

A carat is a unit of weight equal to 200 milligrams, or 1/5 of a gram. A 1 carat diamond therefore weighs 0.20 grams.

The carat is divided into 100 units called POINTS. So a 30 point diamond weighs 0.3 carats.

For the same type of cut, such as a ‘Brilliant’, the greater the weight (carat), the larger the stone. See below:

2. Second C – Colour

To facilitate communication between diamond buyers and sellers, the GIA has created a diamond colour grading standard that begins with the letter D and ends with the letter Z.

The less colour a diamond has, the higher its classification on the scale.

Diamonds with a colour rating between D and F are considered colourless, with D being the rating used for diamonds that are completely colourless.

As the diamond shows more shades of yellow, it moves down the scale until it reaches the R colour grade (letter).

The price of a diamond decreases as the colour increases. From the letter S, the diamond is considered “fancy” and is graded differently.

ABNT/IBGM uses the following definition in Portuguese to translate the GIA colour scale.

Diamond Colour Classification

• D – Exceptionally extra colourless
• E – Exceptionally colourless
• F – Completely colourless
• G – Completely colourless
• H – Colourless
• I – Light colour
• J – Strong colour
• K – Slightly visible colour
• L – Visible colour
• M – N – Light colour
• O – Z – Strong colour
• Over Z (Fancy) – Unusual or unusual colour

The most common colours are

• Yellow diamond – a yellow diamond has nitrogen in its composition. A small percentage of this compound is enough to turn a colourless diamond into a yellowish piece.
• Orange Diamond – Orange diamonds also have a concentration of nitrogen. The only difference is that the atoms are aligned in a very specific way, making this option extremely rare.
• Blue Diamond – the blue diamond is made up of the element boron and can be found in both light and dark versions.
• Red Diamond – The red diamond is the rarest diamond in existence and is only found in Africa, Australia and Brazil. There are also some variations of this colour, such as the pink diamond.

3. Third C – Clarity (degree of purity)

The diamond must sparkle brightly and have an “inner fire” worthy of the most precious of gems.

The diamond’s clarity refers to the presence (or absence) of inclusions and blemishes that could diminish its value.

In Brazil, these blemishes and inclusions are known as “jaça”.

The purity of diamonds is assessed by a professional using a 10x hand lens or a gemological microscope with a 10x lens.

The number, size, position and type of imperfections (flaws) determine the diamond’s clarity. A diamond graded IF (Internally Flawless) is considered the purest.

ABNT/IBGM uses the following definitions in Portuguese to translate the GIA purity scale (see table on next page)

Diamond clarity grade

• FLAWLESS (FL) – Clean inside and out
• IF – Internally flawless
• VVS1 and VVS2 – Very small inclusions or inclusions difficult to see with 10x magnification
• VS1 and VS2 – Very small inclusions, difficult to see with 10x magnifier
• SI1 and SI2 – Small inclusions, easy to see with 10x magnifier
• I1 – Inclusions visible with 10x magnifier
• I2 – One large inclusion or many smaller inclusions, easy to see with the naked eye
• I3 – One large inclusion or many smaller inclusions, very easy to see with the naked eye.

4. Fourth C – Cut (Cut or Polished)

The cut grade of a diamond refers to how the diamond has been cut and polished.

This grading should not be confused with the type of diamond cut (Brilliant, Navette, Oval, etc).

Cut is the most important of the 4 Cs and refers to the quality of the cut.

A well-made cut gives the diamond a brilliance and fire that makes it stand out from other gemstones.

The cut is made up of two very different parameters: the proportions (angles and heights) and the degree of finish (symmetry and polish), which reflect first and foremost the care and experience with which the gem was treated at the time of cutting.

The image below refers to the “Brilliant” cut, which is considered ideal. All angles and proportions have been scientifically defined to ensure the best performance of light inside the diamond and its return to the viewer’s eye, creating the colours and brilliance you see in a high quality diamond.

Diamond Cut

• Excellent – Excellent cut
• Very good
• Good – Good Lapidary
• Fair – Acceptable Lapidary
• Poor

The better the cut, polish, symmetry and brilliance of the diamond, the better the return of light and therefore the higher the value of the diamond.

ABNT/IBGM uses the following definitions, in Portuguese, to translate the GIA Cut Scale.

Return of light in the diamond

• Excellent – Excellent cut
• Very good
• Good – Good Lapidary
• Fair – Acceptable Lapidary
• Poor

 

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