An introduction to diamonds

An introduction to diamonds

In the beginning… - A 10 minute read

The name diamond comes from the Greek word Amadas, meaning invincible or indomitable. A diamond is crystallised carbon created at a depth of about 300 km in the Earth's mantle by a combination of heat and pressure. The conditions of the necessary temperature and pressure listen incredibly closely. This is why diamonds are such a rare product. When the precise combination between high heat and pressure varies slightly, the carbon turns into graphite (from a pencil) or carbon. Diamonds come to the surface via volcanic eruptions. Volcanic pipes are excavated and diamonds are found in them. The main mining locations are South Africa, Australia, Russia, Canada, Angola and Botswana. Diamond history, according to many historians, begins in India, where diamonds were found as early as the 4th century BC. Small quantities of diamonds were discovered in river beds there. These diamonds were traded first in India, and later with other cultures.

Diamonds in Europe

Indian diamonds, along with other exotic goods, slowly made their way to Europe. They were transported by oriental caravan tours, only to be sold mainly in medieval Venetian markets. In the early 14th century, diamonds began to play an increasingly important role in the jewellery collections of many of Europe's richest and noblest families. In 1475, the scaife was invented by the Fleming Lodewyk van Berken. This was a rotating copper disc, impregnated with diamond powder and olive oil, on which a diamond was cut very slowly. This allowed diamonds to be cut symmetrically for the first time.

At the end of the 16th century, more and more experimentation with diamond cutting took place. Thus, Dutch and Flemish diamond cutters started cutting thinner pieces of rough diamonds with a triangular pattern. This would eventually lead to the rose cut. During the 17th century, this form of cutting became very popular.

Rose cut / Rose cut diamonds

The rose-cut diamond was flat at the bottom and was set on silver foil. The silver foil prevented light from passing through the stone, making it look like a piece of glass. By reflecting light with the foil, the light reflected back as the familiar sparkle.The foil is sensitive to moisture and can turn brown or black due to oxidation. Fortunately, this can be replaced, so that the diamond shines again as before. Diamond sawing was introduced in the early 17th century. A thin wire with diamond powder and olive oil was used as a saw to cut through a diamond. This gave more possibilities in diamond shaping.

Octagon cut.

In the mid-17th century, polishing the underside of the diamond was introduced. This was the first step towards the brilliant cut. People tried to give the diamond a round appearance by cutting 8 facets on the crown and 8 facets on the pavilion.

Mazarin Cut

The next important grinding development was done by grinder Cardinal Jules Mazarin. He improved the back grind, grinding 17 facets on the crown and 17 facets on the pavilion. This grind was named after him.

Peruzzi Cut

At the end of the 17th century, Venetian diamond cutter Vincent Peruzzi improved the Mazarin cut with an even more beautiful cut, which especially highlighted the life and fire of the diamond. This cut had 33 facets on the crown.

Old European cut

One problem with the Peruzzi cut was that the diamond was not very proportionally cut, the diamond was often thick and showed very dull and lifeless. This problem was solved in the first quarter of the 18th century when the Old European cut was developed. This cut had a shallower pavilion, was rounder in shape and the facets took on a different pattern. In the early 18th century, the diamond trade shifted. Supplies from India were dwindling and important finds were made in Brazil. In the local rivers, Brazilian prospectors found diamonds in their sieve pans. This discovery would ensure a steady influx of diamonds to Europe and made Brazil the leading diamond exporter for the next 150 years.

Modern diamond trade.

In 1867, the first diamond was found in South Africa, by 15-year-old Erasmus Jacobs, on the banks of the Orange River. He found a 21.24ct pure diamond, later called the Eureka diamond. The Eureka sparked the 'Kimberly diamond rush' in South Africa and transformed it into Africa's most industrialised and developed country. On the Beers brothers' farm in Kimberly, the first major diamond mine was dug in 1871, later to be called 'the big hole'. Here, more than 22 million tonnes of earth were dug out, of which about 3 tonnes turned out to be rough diamonds. In 1888, a group of investors led by Cecil Rhodes established the De Beers Consolidated Mines Ltd. The company was named after the two brothers, on whose farm the first major diamond mine had originated. However, the brothers had no active role in the company. By 1900, the De Beers group had almost a monopoly in the diamond trade. The group controlled as much as 90% of the distribution of the rough diamond trade. The finds in South Africa brought an unprecedented amount of diamonds to the European market. This is also evident in the jewellery made around 1890 - 1915 in the belle époque era. This style (full of diamonds) would have looked different without the finds in South Africa.

Modern Brilliant Cut

In 1919, Belgian engineer Marcel Tolkowski published his thesis for the ideal proportions of a diamond. Using mathematical calculations, he investigated how the maximum light would be reflected from the top of the diamond and reflected back to the viewer. The facets on the crown are designed to refract the white light. The light is reflected back from the pavilion, which acts as a kind of mirror. When the light hits the bottom of the diamond, it is split into spectral colours. This effect, which looks like a play of tiny flashes of colour coming from the diamond when it is tilted, is the dispersion of the diamond (also called fire). So with this formula, Tolkowski came up with the best brilliant cut ever. With all the modern technology, such as light tracking and 3D computer modelling, no cut has yet been invented to surpass the effect of the modern brilliant.

Asscher

In 1902, the famous Amsterdam sharpener Joseph Asscher patented his own cut: The Asscher cut. This cut was revolutionary, at a time when the old European cut was still the norm and the ideal proportions of a diamond were not yet known.

were not yet generally known. The emerald cut developed later was copied from the Assher cut. In 1905, the very largest diamond in the world was found, in the Premier mine in South Africa. This diamond weighed 3106ct and was bought from Thomas Cullinan (owner of the mine) by the Transvaal government for £150,000. They wanted to donate the diamond as a "token of the loyalty of the people of Transvaal to his throne and person", to their king, Edward VII of England. Joseph Asscher was asked to cleave and cut this diamond. On 10 February 1908, after months of research, Asscher decided to cleave the diamond. This process was done by, with a kind of axe (cleaver knife) and hammer, hitting the stone hard so that the stone would split in two exactly along the atomic fault line. On the first attempt, the knife broke, but on the second attempt, Asscher managed to finish the job. There is a legendary rumour that Asscher fainted at the important moment because of the tension. This, incidentally, is denied by the Asscher family itself. The diamond is now part of England's crown jewels. The diamond is placed in the sceptre and can be seen on official occasions.

Diamonds are assessed on 4 important points. This assessment system is called ‘The four C’s’ and stands for:

- Colour

- Clarity

- Carat

- Cut

This system was designed in 1953 by the GIA (Gemmological Institute of America) and is now the international system by which all diamonds are assessed.

Grading diamonds

1) Cut

There is a misunderstanding among Dutch consumers in this area. People are so used to a brilliant cut diamond that diamonds are now called brilliants. This is not correct. A brilliant is a cut and a diamond is the type of stone.

Most diamonds are now brilliant cut. This is because this cut ensures maximum sparkle and brilliance. In principle, light only enters the stone via the crown (top), which reflects it upwards via the facets of the pavilion. See Modern Brilliant Cut and Tolkowski. If a brilliant cut diamond is not cut deep enough, or too deep, the light cannot reflect back properly and the stone ‘leaks’ light. A deep stone can become very dark, but with a shallow stone the girdle can be reflected in the stone. This is also called a fish eye. This affects the value of a brilliant cut diamond. A brilliant cut diamond has 57 or 58 facets (depending on the presence of the culet/bottom) and is an expensive cut.

The average weight loss from rough to brilliant is 50%. Partly because of this and partly because of the high demand for well-cut modern brilliant cut diamonds, they are also more valuable than diamonds that are valued identically but have a different cut.

2) Colour

Diamonds come in all colours of the rainbow. A diamond with an atomic structure that consists entirely of carbon will be colourless. However, in the natural formation process it often happens that the crystal, somewhere along the way, incorporates the trace element nitrogen into its structure. This happens with approximately 98% of all diamonds and these stones fall under the category ‘Cape series’. These stones are colourless to varying intensities of yellow. These diamonds can be purchased at almost every jeweller in the world. The other 2% are colour diamonds and are extremely rare. The yellow tint in the diamonds is caused by minuscule particles of nitrogen in the diamond crystal. The more nitrogen in the stone, the more yellow the colour. For most consumers, the subtle differences are not visible, which is why a trained eye is needed to distinguish the shades. The valuation is done on an alphabetical scale from D to Z. Everything from M to Z is considered yellow and actually falls outside the popular white colour range.

A common question is: ‘why does the colour scale start at D and not just at A?’ There are many myths about this, but according to the inventors of the system it was done because in the past in every country where a bit of serious diamonds were traded, different systems existed for determining the colour. Most started with A or A1 or AAA. To avoid misunderstandings and to distance themselves from these different systems, the GIA chose to start with a new letter that was not yet in use, the letter D.

3) Clarity

The clarity / purity of a diamond is assessed by the amount of inclusions that are visible in the diamond. Most consumers cannot make a good distinction between these and it takes a trained eye to see the subtle differences. Clarity should always be assessed with a 10x magnifying glass.

FL – (Flawless) Nothing visible (also no imperfections on the outer edge)

IF (Internally Flawless) Nothing visible internally

VVS 1&2 (Very Very Slightly Included) Almost nothing visible, only with very careful searching or with the help of a microscope would the smallest spot be visible.

VS 1&2 (Very Slightly Included) Something visible with the 10x magnifying glass but it is difficult to see and is not visible to the naked eye.

Si1 & 2 (Slightly Included) When you look with a magnifying glass, even an untrained eye can find the inclusion. But nothing is visible to the naked eye.

I 1-3 / Pk 1-3 (Included 1 -3 / Pique 1-3) Here the inclusion is visible with, or often without, a magnifying glass.

4) The Carat weight

The standard method of weighing gemstones, and therefore also diamonds, is indicated in carats. 1 carat weighs 0.2 grams. This system comes from a time when there were no accurate scales and people used carob seeds as a standard measure. These seeds happened to always be 0.2 grams. For diamonds, the seeds were not accurate enough and so a more accurate point system was developed. 1 carat was broken down into 100 points. So a 10 pointer weighs 0.10 carat. Diamond prices fluctuate the most with the round sizes, because these are the most commercial. For example, a 0.48ct is a lot cheaper than an identical 0.50ct and a 0.96ct is again much cheaper than a 1.00ct. This is interesting for the consumer who does not attach much value to the round numbers and wants to get the most out of his budget.