The diamond and the 4Cs

The 4C rule: Cut, Color, Clarity and Carat.

It is used to determine the price of a diamond based on a ratio: Cut, Color, Clarity and Carat.

These four qualities make the diamond the most famous of precious stones in jewelry.

The beauty of its brilliance is due to the fact that it has a high refractive index. light and a high dispersive power

 

C No. 1 - The Cut: The Size

The degree of beauty of the dispersion (rainbow effect) of the diamond depends, to a large extent, on the size and polish of the stone.

This diamond grading criterion is the only one that results from the work of the diamond lapidary, and laboratories assign a cut grade according to the table below.

Diamond cutting is mainly done at Antwerp (Belgium), at Tel Aviv (Israel) and at Gujarat (India) by the community Jaine.

Because of its extreme hardness, a diamond can only be machined by another diamond ; therefore, the cut and polish of the stone are the most important elements.

C No. 2 - The Color

Diamonds are also classified by color.

The most common color is " white ".
(absence of color: that is to say that the diamond is transparent and colorless).

These colors are rated from D (purest white) to Z (darkest shade).

The color rating system was established by the independent laboratory GIA.
(Gemological Institute of America).

Diamonds of a different color, such as blue diamonds, are called Fancy Colored Diamonds and have a different grading system.

C No. 3 Clarity: Purity

Diamonds also contain a wide variety of inclusions that can alter their appearance.

An inclusion or impurity in a diamond is nicknamed a toad in France.

Inclusions are indicated using the following codes.

C No. 4 - The Carat: the weight

Photo credit: Rigal Jewelry

The mass of a diamond is measured in carats, which is equivalent to 0.20 grams.

The value of a diamond is exponential with respect to its mass.

In other words, a two-carat diamond is worth more than two one-carat diamonds, since it is considered rarer and therefore more expensive.

Gemological laboratories are responsible for certifying the characteristics of diamonds according to the 4Cs classification.

This certification process involves precise measurements of the diamonds, the assignment of a cut, polish, and symmetry rating, fluorescence analysis, and the assignment of a unique laser-engraved number to each diamond. The individuals responsible for this work are professional gemologists. There are only a few gemological laboratories worldwide; the most well-known are:

^{Gemological Institute of America (GIA) to new York}

^{High Council for Diamond (HRD) to Antwerp ;}

^{International Gemological Institute (IGI) in Antwerp;}

^{GGTL Laboratories, has Geneva and in Liechtenstein;}

^{Fellow of Gemmological Association (FGA) to London ;}

^{American Gem Society (AGS) in New York;}

^{French Gemmological Laboratory (LFG) to Paris .}

 

The diamond dealer (a term originally referring to the diamond cutter), unlike the gemologist, does not study diamonds but trades them.

Depending on their specialty, their activity will involve cut stones or rough stones, with some combining both.