The Diamond

Discover

The Diamond

The ancient Greeks supposed diamonds to be fragments of stars fallen to Earth, others believed they were the tears of the gods. From the Ancient Greek word “adámas” meaning “invincible” or “untamed”, to the Middle English or Old French word “diamant”, diamond stands for lasting value and beauty.

The derivation of the name ‘diamond’ is reflected in the extraordinary hardness of the material. Due to this unique characteristic, diamond is and has always been associated with timelessness and durability. Diamond is not only a symbolic gem because it conveys love, but for even longer it has signified eternity, brilliance and dignity.

The universally accepted method for assessing a diamond’s quality and at the same time, its value, is the 4Cs: carat, colour, clarity and cut.

The Diamond's

Composition

Formed one to three billion years ago in an environment where temperatures reach over 1000 degrees Celsius, and more than 150 kilometres deep beneath the earth’s crust, diamonds were typically released through explosive eruptions from the earth’s interior.

With 99.95 percent carbon, diamond is the only gem that is composed of one single element. This exceptional gemstone forms the hardest material in nature, 10 on the Mohs scale of mineral hardness.

The Diamond's

Colour

When it comes to colour, most diamonds appear colourless. However, the discerning eye will distinguish minimal nuances caused by chemical impurities, which can greatly influence its value. The less visible the colour (the more colourless), the more valuable the gem. Diamonds are graded on a scale from D to Z, D being the highest and meaning completely colourless.

The so-called “fancy-coloured diamonds”, are those falling outside of the normal colour grading scale (D to Z) with a distinctive colour. They exist in virtually all colours, ranging from red, pink, purple, violet, blue, green, yellow, orange to brown. The intensity of a diamond’s colour is often an indication for its rarity, making it a highly-prized gemstone. Black, grey and white diamonds (not to be mistaken with colourless diamonds) are also considered fancy-coloured diamonds.

The

Golconda Diamonds

The most famous historical source for diamonds of the highest standards of transparency, clarity and colour were the Golconda mines. These Indian deposits eventually became exhausted centuries ago and gems from this origin belong to the precious gemstones, which are rarely encountered in the trade today. The term Golconda diamond is nowadays used by some as a quality description of more valuable Type IIa diamonds, which also come from other origins.

Associated with the famous ‘Golconda’ appellation are always Type IIa diamonds, the most valuable of the colourless diamonds as they have almost no impurities, whereas Type I diamonds tend to have some nitrogen trapped in the crystal structure.

The

Main Sources

Historically, the first diamonds were washed out of river gravels 2’500 years ago in India, which was the only known diamond source until the 18th century. With production slightly fading, the supremacy of Indian diamonds got overshadowed by the discovery of diamond deposits in Brazil. At the end of the 19th century, people’s attention turned towards the African continent where diamonds were found in Angola, Namibia and South Africa. Beginning of the 19th century, diamond production also started in Australia, which until 2020 counted as one of the world’s largest diamond production by volume, entirely thanks to the very famous Argyle Mine. Today the major commercial diamond producing countries are in Russia, Botswana, Canada, Angola, Namibia and South Africa.

Treatment &

Synthetic Diamond

Very few diamonds are treated, however some treatments exist to alter their colour and their clarity with the help of different techniques. Most treatments involve the use of high pressure-high temperature (in a hydraulic press), irradiation, heating or a combination of these in order to improve the colour or create a different one. Lower quality stones can be drilled with a fine laser to reach black inclusions and bleach them. These as well as other visible fissures can then be filled with a transparent material in order to hide them and improve the clarity.

Synthetic diamond is essentially the same material as natural diamond, except that it is man-made. Crystals are grown from a carbon source with two major techniques: HPHT (High Pressure High temperature) and CVD (Chemical Vapour Deposition). The first technique, while is also used to treat diamonds, is the classic method to grow synthetic diamond by pressing a crucible filled with graphite powder. Chemical Vapour Deposition was invented later. It uses hot carbon-based gases, which are deposited as diamond onto a plate. The process consumes less energy as requires much lower pressure.

Although synthetic diamonds have been manufactured for decades already, they were never really much of a topic since the cost of production was very high and their size and quality rather limited. This has been changing in recent years since the quality and size of synthetic diamonds have improved dramatically while the cost is rapidly and steadily decreasing.