Comment classer les diamants

Classement des diamants : Ce qu'il faut savoir

The intrinsic value of diamond jewellery primarily stems from the diamond itself. Grading diamonds is a nuanced process because even minute differences, often invisible to the naked eye, can significantly affect the price. It’s precisely why the industry relies on certified gemologists in specialized labs to accurately grade diamonds.

For those not in the gemology field, accessing a gemologist may not be immediate, but you can easily schedule a consultation with one of our experts today by calling 1-888-219-7001.

If you’re considering a diamond investment, such as an engagement ring, this straightforward guide will help you grasp the crucial aspects of diamond buying.

Starting with the 4 C’s—Carat, Cut, Clarity, and Color—we aim to enhance your understanding of diamond anatomy and grading standards:

Carat

Carat refers to the weight of a diamond, with one carat set at 0.2 grams. This term originates from the carob seeds once used for balancing scales due to their consistent weight. While carat weight suggests size, higher carat diamonds command exponential prices due to their rarity. 

Bien que le carat mesure le poids du diamant, il permet généralement de déterminer sa taille. Voici un tableau des diamants "ronds" indiquant leur carat et leur taille relative en millimètres.

Plus le carat est élevé, plus le prix augmente de manière exponentielle, car les diamants de plus d'un carat sont beaucoup plus rares. Un diamant de deux carats vaut plus par carat qu'un diamant d'un carat de même qualité.

What carat to purchase is all a matter of budget and personal preference.  If you would like to get a better comparison of different diamond sizes, view our Diamond Size Chart.

Couper

Contrary to common belief, ‘cut’ does not refer to a diamond’s shape but its facets’ arrangement, affecting how light is captured and reflected.  This is also termed as its “brilliance”. In combination with clarity, a extremely well cut diamond will showcase the inherent beauty of the stone where a moderately well cut diamond will limit the interplay between the stone and available light when viewing it.

Les notes de coupe vont de Idéal, Excellent, Très bon, Bon, et ensuite Passable et médiocre. For a typical round brilliant cut diamond, the overall depth and table size are in a tight range that must be adhered to in order to achieve an “Ideal” rating.

Clarté

This grade evaluates the inherent imperfections in a diamond—external blemishes and internal inclusions. Under 10x magnification, grades vary from Flawless to Included, with the cleanest diamonds being the most valuable. Remember, flaws at certain clarity levels are not visible without magnification.

Les taches sont des défauts visibles à la surface, comme les éclats et les rayures, et les inclusions sont des défauts présents à l'intérieur du diamant, comme les bulles, les fissures et les mouchetures minérales.

The clarity grades are evaluated under 10x magnification (inclusions in grades F through VS are pas visible to the naked eye).

Couleur

Diamond colour grading actually assesses the lack of colour, with a spectrum from colourless (D) to light yellow (Z). The less colour a diamond exhibits, the higher its value, except in the case of rare coloured diamonds like blues and pinks. Unlike a typical white diamond, these stones are prized for their unique color.

For traditional diamonds, the more colourless the diamond, the more it will emphasize its brilliance as made evident by the diamond’s couper.

Le 5e "C" : Les certificats

A diamond certificate provides a reliable report of the diamond’s 4 C’s, assessed by a professional using precise tools. This ensures that you are getting what you pay for. Certificates are typically issued by organizations such as GIA or AGS. Because the 4 C’s are often impossible to recognize to the untrained eye, it’s important to make sure a professional has gone over your diamond(s). 

Diamonds are an expensive investment. The smallest detail could drastically affect its value. If you’re buying diamonds or diamond jewellery, it’s always preferable to purchase stones with a certificate.

Forme (Style)

While not as impactful as the 4 C’s, the shape of a diamond does influence aesthetic appeal.  Preference for certain shapes is unique to the individual, however not all diamond shapes are ideal for all settings.  This makes shape an important consideration for stones not yet set in a ring or other jewellery.  Many popular shapes include:

(Il est à noter qu'un diamant de cœur d'un carat pèsera le même poids qu'un diamant rond d'un carat, mais cela ne signifie pas qu'ils auront exactement la même taille).

Armed with this knowledge, you’re now ready to make informed decisions about diamond purchases. For direct assistance and to schedule an expert consultation, call us at 1-888-219-7001.