Diamond Carat

Diamond, a mass of light, is not represented. Any figuration of this precise stone is below, next to, reality. A loss. The figuration of the weight of the diamond? What the eye sees is not the weight, it is a volume, a brilliance. A diamond appears much larger than its diameter, by the play of brilliance of these facets.

The diameter? The carat, unit of measurement, measures weight and not diameter. A 1 carat diamond is not twice as large as a 0.50 carat diamond, only 25-30% larger (see table on the right), but costs more than double that. To help you better visualize the size of a diamond, we indicate in the table below the approximate diameter of a diamond (round brilliant shape) according to its carat weight.

In the Jewelry section of our site, on each of the jewelry cards (of solitaire, rings, pendants and earrings), you will also find a carat comparator that will allow you to visualize the visual effect of a diamond set and worn (on a hand, a bust, an ear), according to its carat weight and its diameter.

Please also note that the precise dimensions of the diamond are always indicated on the GIA, HRD or IGI quality certificate. You can see the online copy of the certificate by clicking on "see certificate" of each diamond card from our certified diamonds catalog.

A diamond, whether big or small, does not weigh much, but it is the factor that "weighs" the most on the price. This is why in our diamond catalog, we start with the weight and a price range, and then refine the other criteria.

There is no single answer to the often asked question: "what is the price per carat of a diamond? Two diamonds of the same weight often have very different values: it all depends on their certificate, quality of cut, shape, color and purity.

The question is then to know which diamond quality criteria you prefer according to your budget.

It is because the price of the material is high that the diamond is weighed accurately. The unit of weight in carat is a determining factor in the quality and value of a diamond. The value of a 1.00 carat stone is exceptionally greater than a 0.99 carat stone. Diamonds are weighed using electronic microbalances with a sensitivity of up to five decimal places. Verification of the weight of the stones throughout the diamond chain is also an important security measure.

Whether the diamonds set on your jewelry looks big or small, the simplest method (without having to loosen the gemstones in the jewelry) is to measure the diameter of each one. With the cross-reference chart above, you can determine the carat weight of the diamonds in your jewelry. Attention this rule works for white diamonds and colored diamonds (pink, yellow diamonds...), whatever the degree of purity and color, but does not apply to other gems, precious stones (Sapphire, Ruby, Emerald) or fine stones, whose density is different. For an exact measurement of the dimensions of gemstones, it is still best to go to a jewelry store and ask for the help of a professional jeweler, because even with a calliper, measurement errors are easy.