The diamond in all its facets Paris Match | Published on 03/15/2022 at 04h00Fabienne Reybaud

This diamond is a flirt. Its dazzling sparkle gives it a pleasurable plumpness: it seems to weigh more than 1 carat while its weight is only 80 hundredths… With its new empress cut, Chaumet has just performed a small miracle by multiplying the fire of the diamonds in its Bee My Love collection. “This hexagonal cut with 88 facets, developed with Canadian and Antwerp diamond dealers, makes it possible to significantly increase the brilliance. The angle of light reflected by an empress-cut diamond is greater, 48 degrees, compared to 35 for a round diamond,” observes the Chaumet stone manager. Moreover, their brilliance is such that the jeweler has decided not to use the empress cut on stones over 3 carats, so as not to give in, it seems, to the sirens of bling-bling diamonds…

In fact, when you visit a carving workshop in Tel Aviv or Antwerp, the story that comes to mind is that of the ugly duckling transformed into a swan. Or how, by the work of a diamond lathe or a laser machine, man manages to transform a greyish pebble, which, at best, looks like a piece of ice or debris from glass, in brilliant gems. “In front of each rough stone, we ask ourselves the same question: how to optimize it in terms of shape, color, clarity? Depending on the type of size, we lose between 40% and 50% of material. And every carat less is wasted money. Every hundredth is worth hundreds, if not thousands of dollars. We have no room for error,” says an Israeli diamond dealer.
Appearing in the 1990s, the first scanners which reveal the interior of the rough before the cleavage of the stone make it possible to determine the number of facets and the shape to be given to the diamonds. In the same decade, laser cutting, which is more precise than that performed by human hands, became widespread.

If a good professional still knows how to appreciate by eye what he will get from his rough diamond, giving the best of the gem by cutting remains a relatively new science since it dates back to the 20th century. Previously, the methods were more empirical. The Middle Ages were content with the “point cut”, consisting of polishing the eight natural facets of the octahedral crystals of rough diamonds. Then in the 16th and 17th centuries, the importance of symmetry and the addition of facets made it possible to increase the reflection of light. In the 19th century, the “old European cut” with 58 facets was the ancestor of the contemporary round cut as defined by Marcel Tolkowsky in 1919. This Belgian mathematician published a treatise, “Diamond Design”, in which he gave the ideal dimensions for a stone to have maximum brilliance, fire and sparkle. By theorizing on the “brilliant round” shape, with 58 or 57 facets, Tolkowsky is considered the father of the modern cut.

The pear and the oval, which have the virtue of lengthening the finger, are on the rise

Today, 75% of the stones sold in the world are round brilliant cut diamonds. So much so that all the other shapes (pear, emerald, baguette, etc.) are called “fantasy” in the profession. Having become the archetype of the engagement ring, the brilliant cut diamond has the defects of its qualities. “It’s a classic, it’s reassuring for the general public because it’s the reference value for 1-carat diamonds. When the cut is done well, the brilliant cut – which, as its name suggests, shines a lot – is always beautiful. But for stones over 5 carats, in order to avoid the carafe stopper effect on the finger, it is better to favor other types of cuts, such as pear, oval, cushion, which are more elegant » , observes the head of gemstone purchasing at Van Cleef & Arpels. In the family of faceted cuts, the pear and the oval, which have the virtue of lengthening the finger, are on the rise. More difficult to cut – the play of light can create a dark effect called “butterfly wings” inside the stone – these two shapes do not support bad proportions. “If the pear is too big and the oval too wide, we call them ‘potatoes’ in our diamond jargon,” confides a professional. An ugly cut never makes pretty jewelry. »

As for the princess cut, although it had its heyday at the end of the 20th century, it is now rarer in the collections of jewelers in Place Vendôme. Its 76 facets distributed in a square shape provide an exuberant shine that remains very flattering on stones under 1 carat. Conversely, a cushion-cut diamond does not lend itself to modest carats because its head is thick. Clearly, at equal weight, it may appear smaller than a classic brilliant. Nevertheless, its undeniable charm, the harmony of its proportions and its rich past (the most famous diamonds in the world such as the Hope, the Cullinan II or certain stones from the collection of Cardinal Mazarin are cushion-cut) have kept many aficionados. In another style, the marquise cut would have been created in the 18th century on the model of the lips of the Marquise de Pompadour, mistress of King Louis XV. This shuttle diamond shape, in vogue in the 1950s and 1960s, is still rarely used as a center stone, probably because its two points can make the jewel more fragile. However, its shape gives the illusion of thinning the finger, and the stone seems more important than its real weight.

Also read.Will the diamond wars take place?

In addition to the faceted cuts, the diamonds can be the subject of a step cut which, whatever its shape, offers less conspicuous fires, a undoubtedly sharper shine. This is the case of baguette diamonds, ubiquitous in Art Deco jewelry. Or the famous and timeless emerald cut, a rectangle with cut sides. “An emerald-cut diamond must have perfect quality and color because the smallest inclusion will be obvious because it cannot be concealed by a facet,” says Matthieu Brichet, head of European markets for jeweler Graff. In exchange, this sleek diamond looks bigger thanks to a larger table surface…

Any reproduction prohibited