"Choosing a diamond may seem complicated so it is best to do some research before you dive into selecting the perfect ring for your beloved. Our professional team here at Tresor Paris are well equipped to answer any queries to assure you get the best possible value and quality. We recommend booking an appointment so one of our diamond experts can show you a selection of our handpicked diamonds enabling you to make an eye view comparison.

All of the diamonds are individually picked and inspected by our specialists who are members of the elite London Diamond Bourse. We ensure that not only we select excellent quality diamonds but those which have the most fire and sparkle."

The Four C’S

A diamond’s quality is defined by the 4 C grading system though we recommend your final decision is based on which one calls to you as each diamond has a different character.


Diamonds are measured on their weight by the metric term ‘carat’ which can be divided into 100 points allowing precise measurement. The term carat derived from carob seed which was once used to weigh diamonds. The higher the carat weight the more the value increases, larger diamonds are very rare which equate to their high value. It is important not to confuse the carat weight with the size as the cut of the stone will differ, with some carrying the weight in the depth of the diamond. Deeper stones often reflect the light better giving maximum sparkle however you can get good value for money if you are after a larger table top stone but it is slightly more shallow.


The cut is in regards to the shape of the diamond, the most popular and versatile is the Round Brilliant. There are many different options but common ones include: Emerald, Pear, Oval, Princess, and Marquise. The beauty of a diamond is demonstrated when it interacts with the light, a well-cut stone will reflect the light back out at you after it has entered the crown. The cut is also judged by the fire which refers to where the light disperses into the colour of the rainbow. The better the cut, the more sparkle. If a diamond is cut too shallow or deep the light may escape through the side making the diamond appear dull.


The colour is graded on an alphabetical scale from D to Z, D being colourless which is the rarest and best quality which is reflected in its premium price as you go down the scale the diamond with have an increasing brown or yellow tint. The colour scale is more prominently divided into 3 main categories D-F being colourless, G-H Near Colourless & I and above is Tinted. Most stores carry only stones of D to J however we are more than happy to show you other colours on request.


The clarity determines the size of the impurities that form inside the diamonds called inclusions. Diamonds are a natural material for which each carry their own ‘fingerprint’ detected by their unique internal characteristics. The rarity of a diamond increases with its purity. The diamond grades for these inclusions are across a few categories with subdivisions. Internally flawless, very very small inclusions, very small inclusions & small inclusions. Often the majority of the imperfections cannot be seen with the naked eye unless looking at the stone under 10x magnification.