The 4C


The main criteria for assessing a diamonds quality, explained for beginners.

Carat, cut, color and clarity are the main criteria for describing a diamond. But what exactly do they mean?

1. Carat

“Carat” is not a measure of size, but of the weight of diamonds and other gemstones: One carat corresponds to 0.2 grams.

Since small differences in the carat weight can cause a huge price difference, measuring is conducted with great precision: Carat weight is often measured to the hundred-thousandths of a carat. However, you’ll find the carat weight declaration rounded to the hundredth of a carat on most diamond certificates.

Although Carat might be the most commonly known characteristic of diamonds, the value and quality of a diamond also depend on the other C!

Try our ring configurator to simulate how a ring looks with differently sized diamonds!

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2. Cut

When it comes to cut, you need to differentiate between the shape or cutting style and the cut grade of the diamond: Shape and cutting style as shown on a GIA certificate describe the actual form a diamond was cut into. The cut grade measures the craftsmanship quality of the cutting process. It’s the cut quality that gives a diamond it’s sparkle and brilliance: The appearance of a diamond largely depends on the quality of its cut.

The scale assessing the cut on a GIA certificate ranges from Excellent to Poor. Each one of these grades represents a whole range of proportion sets and face-up appearances.

Click here for more detailed information on the cut and shape of a diamond.

3. Clarity

Diamonds consist of only a single element, which is carbon. Intense heat and pressure over a long time turn the carbon molecules into a diamond. However, every diamond contains unique internal or external “birthmarks”, called inclusions (internal) and blemishes (external).

It is the inclusions and blemishes that make a diamond truly unique and unmistakable. Some diamonds come close to perfect, but most jewelers have never seen one.

The diamond's clarity, which measures the absence of inclusions and blemishes, is described by terms like FL (Flawless) for diamonds with no visible inclusions under 10x magnification, VVS for very slightly included or I for inclusions that are visible under the magnifying glass and may affect transparency and brilliance.

More on the clarity scale applied by the GIA.

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4. Color

Color measures how white a diamond is. D-colored stones are absolutely colorless, which is what is most sought after. On the lower end of the scale, diamonds with a Z color grade have a light yellow or brown tint. Each grade in-between D and Z stands for slightly different shade. While the differences between them are often hard to see for the untrained eye, they still contribute to the value of a diamond.

More on the GIA color grading scale

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The 4C




Weight and size



Shape und cut quality

Excellent - Poor


Absence of carbon inclusions

F (flawless) - I (included)


Absence of a yellow tint

D - Z

Finding the right trade-off between the 4Cs

It’s crucial to find the right trade-off between the 4Cs that right for your ring and budget. Click here for My Diamond Ring’s guide to finding the right trade-off.

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