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Diamond explanation

4 Cs


The weight of a diamond is expressed in carats. One carat equals 0.2 grams or 100 points.

Color = Kleur

Most diamonds range in colour from white to pale yellow. However, diamonds come in many colours, ranging from brown to bright yellow, pink, purple, red and blue. These are the so-called 'fancy colours'.

The colour of a diamond is determined when we compare it with sample stones under standardised artificial light. This light is equivalent to the Northern daylight. The indicated colours in the image are only meant to indicate the difference in colour nuances.


A diamond is flawless when it is free of internal flaws. An experienced expert looks at the diamond with a magnifying glass that magnifies 10x under normal light. The other qualities are determined by the size, position, the brightness and the number of internal flaws. External and structural flaws are listed separately. The lowest purity level (indicated with 'p' for piqué) refers to inclusions that can be seen with the naked eye.


The cut of a diamond is essential to its beauty. If the diamond has not been correctly cut, the diamond will have less interaction with the light. Even a diamond with excellent colour and clarity will not show the fire and brilliance that diamonds are famous for.

All diamonds are beautiful, however, only acquaintance​ with the 4 Cs helps you to discover your personal vision of beauty and your diamonds. Not every diamond is the same. It mainly depends on a perfect finish: diamonds that are too sharp or cut too flat do not reflect the light well. Gassan Diamonds has almost seventy years of experience in diamond cutting. We ensure the right diamond proportions and quality finishing.

You purchase a diamond based on trust. A good jeweller or goldsmith will not only advise you with his expertise, he will also carefully guide you and clearly explain the quality system by means of the 4 Cs. He will invest significant time and effort in this. He will advise you in selecting the right jewel.

Ultimately, a reliable jeweller is your guarantee that you will make a good choice. As an expert, he attaches great importance to his reputation and he will advise everyone correctly on the best quality diamonds in every price range.