Fake diamond and synthetic diamond, what are the differences?

Since its discovery, the diamond has fascinated men.

While the origin of its exploitation dates back 3000 years ago in Indiait was precisely its exceptional hardness that first made it famous and pushed men to give it magical powers, using it as a tool amulet worn in the form of a rough diamond.

Although today the diamond is best known for its brilliance, it was not until the mid-14th century that diamond cutting techniques were developed.

Previously, diamonds worn in jewelry had the appearance of the dull rough diamond like the one seen in the following photo.

Opaque rough diamond visible from two different angles, read our article on rough diamonds

Natural formation and synthesis by man

Diamond is a crystal made up of carbon atoms organized in a cubic lattice. which forms naturally in the bowels of the earth between 150 and 200 kilometers deep.

Extreme conditions of temperature (from 1,100 to 1,400°C) and pressure (60,000 bar) are necessary for the mineral carbon present in the Earth’s mantle to crystallize. Buried in this way, volcanic eruptions bring diamonds to the surface.

It was only in 1797 that a scientist demonstrated that diamond was made of pure carbon, then only in the mid-20th century did chemists manage to synthesize it.

If we all have in mind the use of diamonds in the jewelry sector, it is precisely the sector that is pushing to develop industrial diamond production processes, which have a great need for hard materials.

However, diamond is the hardest material known so far.

Applications

When it first appeared in the industry, diamond was primarily used for its hardness and was used for cutting tools.

Today its optical properties allow it to be used for sensor design, its biocompatibility allows it to be used for medical applications and its neutrality with respect to bases and acids allows it to be used for electrochemistry.

Finally, it is also starting to be used as a semiconductor in advanced electronics. To learn more about its industrial applications, watch this CEA video.

Manufacturing process

There are currently three techniques for synthesizing diamond:

• HPHT (High Pressure, High Temperature): aims to reproduce the natural process of diamond formation in a reactor by subjecting carbon to the temperatures and pressures necessary for its crystallization (lasting a few hours).
• CVD (Chemical Vapor Deposition): Diamond is created in thin layers by deposition from a plasma.
• Ethanol: A water/ethanol solution is vaporized creating a diamond deposit on the target support.

Schematic diagram of the HPHT process with a rough diamond produced by this method.

Fake diamonds

Synthetic diamonds should not be confused with fake diamonds.

Artificial diamonds are in fact real diamonds, produced by man with industrial means.

These physical, chemical and optical characteristics are in every way identical to those of a diamond extracted from a mine (their differentiation from real diamonds also poses some problems in the jewelry sector).

Fake diamonds are stones of a nature (physical and chemical properties) different from diamonds that can be visually confused with diamonds. This is why if there is any doubt about the authenticity of a stone we will call a gemologist.

To imitate diamonds, various natural or synthetic crystals are used:

• Zirconia (CZ for Cubic Zirconia): Zirconium oxide (ZrO2) is a ceramic used in its transparent form to imitate diamond. Please note that it is not to be confused with zircon, a natural crystal with the formula ZrSiO4.
• Moissanite : This is silicon carbide.
• White sapphire
• Garnet (YAG): This is a synthetic YAG garnet for yttrium aluminum garnet.

source scheme

Given the differences in physical properties between diamond and its imitations, there are several techniques to differentiate them.

Rather than repeat them, I invite you to consult these two sites which give you more information on the subject here and on this page.

And in the jewelry sector?

Natural diamond, real synthetic diamond or fake diamond?

How to orient yourself when you want to buy diamond jewelry?

It’s easy to distinguish real diamonds from their imitations…

While in the past synthetic diamonds were too small and of poor quality to be used in jewelry, techniques have evolved and synthetic diamonds can now be purchased online.

Their interest, as you can imagine, is the very advantageous price of these stones produced with industrial means, which can cost half their natural equivalent.

You can try to evaluate the authenticity of a diamond yourself, but to be sure it will be best to contact a professional.

Especially since if you conclude that your diamond is real, it will be impossible for you to know whether it is an artificial or natural diamond.

Gemologists themselves need state-of-the-art equipment to test stones to determine whether they are artificial or natural, since the latter are so similar.

How to distinguish a synthetic diamond from a natural diamond?

Because the stakes are so high, global diamond leader DeBeers has taken the bull by the horns and developed three systems to detect synthetic diamonds.

However, in the diamond kingdom not everything is rosy: between those who try to sell synthetic diamonds for natural diamonds and the testing machines that classify natural diamonds as synthetic, there are snags whose financial stakes are enormous for diamond traders and whose image risks being tarnished. This article will tell you more about the topic.

Left diamond mix tested by DeBeers AMS (Automated Mele Screening)

From a legal point of view, French legislation provides in article 4 of decree no. 2002-65 of 14 January 2002 relating to the trade of precious stones and pearls, that the sale of synthetic diamonds must be carried out specifying their synthetic nature.

It is therefore illegal to sell synthetic diamonds for natural diamonds, but it is legal to sell them as diamonds (because that’s how it is).

Only the issuing of a certificate of conformity will allow you to ascertain the nature, characteristics and value of your diamond.

For high-value diamonds it is essential to request such a certificate or to have one established. Generally, guarantee certificates are issued for diamonds larger than or equal to 0.5 carats. You can find out more about certification bodies by following this link.

The price of this certificate varies from a few tens to hundreds of euros, we refrain from establishing one for small diamonds generally used in flooring whose value does not exceed a few tens of euros.

I invite you to watch this video report on the topic:

Where to buy synthetic diamonds?

If the production of synthetic diamonds is recent, that of goldsmith-quality diamonds is only a nascent industry. Only a few companies offer their service online, as far as I know, there are none in France. You will therefore find to buy synthetic diamonds in the USA:

By visiting these sites, you will see that although they are not natural, these diamonds are still quite expensive. However, they remain a good solution for purchasing a diamond at a good price and then having it mounted on a jewel.

To go further: