Everyone once asked the question of how much these magnificent diamonds that we see worn by stars and other wealthy (and rare) women around the world could cost.

How to determine the price of this material so special that it has its own unit of measurement? In addition to this essential criterion, there are 3 other elements: the size of the diamond, its purity and its color . Note that if one of these criteria is not known, the exact determination of the value of the diamond is impossible.

Diamond dealers, jewelers and other diamond professionals call these criteria "the 4 Cs".


It is important to specify that the term carat is also used to designate the purity of gold, knowing that 24 carats is equivalent to almost pure gold (99%). The gold most used in jewelery is 18 carat gold, which is increasingly called "750/1000 gold" to avoid confusion with the carat, the unit of measurement for diamonds.

It is the carob tree which would have given its name to the carat. Its seeds, weighing about 0.20 grams, were used as units of measurement to weigh diamonds.

1 carat is therefore equal to 0.20 grams (200 milligrams)

The carat is divided into 100 points (1 diamond of 0.5 carat = 50 points = 1/2 carat)


It is essential. This is not about the shape of the diamond but about how it was cut . Clever calculations have made it possible to determine the ideal proportions of a diamond. Those that would allow the light to reflect on all the facets in a mirror game, creating the so fascinating "diamond fire".

All the proportions of the stone are therefore scrutinized and compared to this ideal stone: its total depth, the width of its table, the angle and the height of its crown ... The symmetry of the stone must also be analysed.


A stone without internal or external flaw does not exist (remember that the diamond is a natural material). Diamonds approaching this perfection are extremely rare and this is what justifies their inestimable value . International standards provide that the analysis of the purity of a stone is done using a binocular magnifying glass magnifying 10 times their size. A diamond will thus be qualified as "pure" if no fault is detected at this stage of the analysis.

What experts are looking for is anything that could alter the brilliance of the stone : the presence of possible inclusions which are tiny crystals and minerals embedded in the stone. It can be crystalline or even other microscopic diamonds.

Irregular crystallization can also cause white growth lines to appear. Experts will also check the diamond for cracks that can range from tiny feathers to cleavage (ie a clean separation).

For greater clarity, a scale of purity has been set up which goes from FL (from English “flawless”) to P3 (prickly):

- FL ( Flawless): no internal or external fault (magnification by 10).

- IF ( Internally Flawless ) or LC ( Clean magnifying glass ): no inclusion (magnification by 10).

- VVS1 and VVS2 ( Very Very Small Inclusion(s) ): tiny inclusion(s) very difficult to see with a 10x magnifying glass.

- VS1 and VS2 ( Very Small Inclusion(s)): very small inclusion(s) difficult to see with a 10x magnifying glass.

- SI1, SI 2, SI3 ( Small Inclusions ): small inclusion(s) easily visible under a 10x magnifying glass, invisible to the naked eye from the side of the crown.

- P1 ( Sharpness 1 ): inclusion(s) very easily visible with a magnifying glass magnification by 10, hardly visible to the naked eye seen from the side of the crown and not affecting the shine.

- P2 ( Sharpness 2 ): large and/or numerous inclusion(s) very easily visible to the naked eye from the side of the crown and slightly affecting the shine.

- P3 ( Piqué 3 ): large and/or numerous inclusion(s) very easily visible to the naked eye from the side of the crown and directly affecting the brilliance of the diamond.


It is a key element in determining its value. The whiter (colorless) a diamond is, the greater its value. This color is appreciated by placing the stone on a very white paper under a white and cold light. This context makes it possible to evaluate how much it deviates from the absence of color.

The color scale starts at the letter D (from the English "diamond") and goes up to the letter Z. The D therefore corresponds to excellence. It is preferable to choose a diamond whose color is between D and I, because beyond that, the brilliance may not be there. Rivluxe sells only diamonds between D and H.

Color scale:

- D, E, F: colorless diamonds (according to the GIA scale, exceptional white +, exceptional white and rare white +, according to the HRD)

- G to J: almost white diamonds (according to the GIA scale, extra white, white, nuanced white according to the HRD)

- K to M: slightly tinted diamonds

- N to P: very light yellow diamonds

- Q to Z: yellow diamonds

August 31, 2022

RivLuxe, spécialiste de la joaillerie d’occasion

RivLuxe vous propose un large choix de bijoux d’occasion remis à neuf par nos artisans joaillers français. Vous pouvez y retrouver de nombreuses grandes marques comme CartierBoucheron, ChopardRolex… Peut-importe l’occasion, notre large choix de bijoux d’occasion vous permet de trouver le cadeau parfait pour vous ou vos proches.