DIAMONDS IN JEWELRY

It is a mineral with a very high refractive index—in fact, the highest of any crystal.
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This unique characteristic allows light to travel through the stone with great ease, giving it incomparable brilliance.
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Beyond this characteristic, the diamond is also renowned for its quality. What defines this quality? That is what we will look at now.
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DIAMOND QUALITY: THE ESSENTIAL "4 Cs"
 

To determine a diamond's quality, the "4 Cs" method—developed by the Gemological Institute of America (GIA) in 1931—is used.
 

Did you know?
 

The GIA is a leading authority in the diamond industry. Based in New York, it was the world's first gemological authority. Today, it certifies the vast majority of certified diamonds in circulation.
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In addition to the GIA, other well-known and prestigious certification bodies include the HRD Antwerp (Hoge Raad voor Diamant) and the IGI (International Gemological Institute).
 

What do these 4 Cs stand for?

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1. The first C is for Carat
 

This refers to the measurement of the stone's weight.
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This first C—carat—is particularly important, as it is a major factor in determining the price. Diamond pricing rises exponentially with weight; therefore, the higher the carat weight, the higher the price.
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Note: A diamond's price is not directly proportional to its weight. For example, a 1.5-carat diamond weighs three times as much as a 0.5-carat diamond, yet its price can be 5 to 7 times higher.
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In practical terms, a difference—even a tiny one—of 0.2 or 0.3 carats between two stones can significantly increase the price of a diamond piece of jewelry!

Isn’t the term "carat" also used for the quality of precious metals? Yes, that’s true, but it means something different; the two shouldn't be confused!

For a stone, the term "carat" refers to a measurement of its mass or weight, where 1 carat equals 0.20 grams.

For a metal, the carat is a unit of measurement for the purity of precious metals like gold. It is the term used to describe the metal's quality—for instance, 18-karat gold.

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2. The second C stands for Color
 

The less color a diamond has—meaning the closer it is to pure white—the higher its quality.
 

The diamond industry uses a color scale to grade diamonds by quality. The scale ranges from D to Z. Here are a few examples:

• D corresponds to "Exceptional White +" (the purest white for a diamond).

• E corresponds to "Exceptional White."

• G corresponds to "Extra White +."

• H corresponds to "Neutral White." 

• ...

• M through Z correspond to tinted or pale yellow shades.

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This color assessment corresponds to the first letter in the famous three-letter codes used to define diamonds, such as GVS, HSI, or DIF.

Note: High-end jewelry houses use only stones graded between D and H to ensure a luminous color and transparency in every stone.

We offer our clients only the highest color grades available—specifically, D through G.
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3. The third C stands for Cut
 

A diamond's cut refers to its faceting—literally, the shaping of its facets.
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This is of paramount importance to the stone's ultimate beauty, as the faceting is what reveals its brilliance.
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In its natural state, a diamond is known as "rough"—often an opaque, misshapen mass. A perfectly executed cut transforms a rough diamond into a dazzling stone by allowing light to diffuse easily through it, thereby fully utilizing its potential for high light refraction.

Conversely, a poor cut will make the stone look dull, regardless of its inherent purity.
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Note: While this point is essential for diamonds, it applies equally to all other gemstones!
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How is a diamond's cut graded?
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A diamond's cut is measured by a "cut grade," ranging from Excellent and Very Good to Good, Fair, or Poor.
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We guarantee a selection consisting exclusively of diamonds with an "Excellent" or "Very Good" cut—the highest grades possible.
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Be aware that "Good" or even "Fair" cuts prevent the diamond from fully displaying its brilliance!
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4. The fourth C stands for Clarity
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Clarity refers to the presence of inclusions within the stone. The fewer inclusions a diamond has, the higher its clarity grade.

What is an inclusion? An inclusion is a foreign mineral or imperfection that became trapped inside the stone during its formation. This process is completely natural for a gemstone; in fact, it serves as proof that the stone is not a lab-grown synthetic.
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Like color, clarity is measured on a scale ranging from FL to P2. Here are a few examples:

• FL (Flawless): No internal or external flaws visible under 10x magnification.

• IF (Internally Flawless): No inclusions visible under 10x magnification.

• VS1 and VS2 (Very Slightly Included): Inclusions that are difficult to see under 10x magnification.

• SI1 and SI2 (Slightly Included): Inclusions visible under 10x magnification but invisible to the naked eye.

• ...

• P2: Inclusions are visible to the naked eye.

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This clarity assessment corresponds to the last two letters in a diamond's quality grade—such as GVS or HSI.
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The 4 Cs therefore stand for Color, Cut (facet quality), Clarity, and Carat (weight)—all the characteristics needed to define a diamond's quality.
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Consequently, every diamond comes with a certificate of authenticity detailing the 4 Cs we have just discussed!

Do you own a diamond without a certificate or with an old report? We can re-evaluate its quality based on current standards. Discover our diamond valuation service in Nice.

All our diamonds over 0.3 carats come with a certificate.

Issued by the GIA (Gemological Institute of America) or the HRD in Antwerp, this certificate acts like a passport—a unique identity document for each stone.
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Why are these certificates so important?
 

First, they guarantee that the diamond's quality has been assessed impartially by independent international bodies, leaving no room for doubt regarding their objectivity.
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These certificates are also important because they ensure the traceability of the stones and support ethical commitments.

Ethics are a priority for us—as evidenced by our 100% French manufacturing—so we source our diamonds from suppliers who strictly adhere to the Kimberley Process, ensuring that none of our stones originate from conflict zones.
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Finally, our diamond suppliers all hold RJC (Responsible Jewellery Council) certification—a highly regulated standard that guarantees ethical and responsible mining practices.