Know the 4 C’s

The identification of diamonds, which determines their market value, is made by expert gemmologists according to internationally agreed norms that refer to combination of features known as the 4C’s: Clarity, Color, Cut and Carat. The 4C’s are a universal and effective way of communication for members of the diamond industry.

Carat Weight

The metric carat is the international unit of measurement of diamonds and other gemstones and it determines their weight. One carat (1ct) equals one fifth of a gram (0.200g) and this enables us to know a stone’s weight in order to give it a value in the market.


People outside the diamond industry tend to misunderstand the relationship between diamonds and colour. In fact, truly colorless diamonds are quite rare. Most diamonds that we see in the market have a slight tint of yellow and brown. The normal colour range is a set developed by the GIA (Gemological Institute of America) labs that help experts all over the world to determine the colour of a diamond, depending on the amount of yellow it has in its chemical composition. Two diamonds with the same clarity, cut and weight can differ a lot in value, based in colour alone. Therefore, GIA developed a system of letters to help you understand the colour of your diamond. In this scale, diamonds range from D to Z, D being completely colorless and, therefore, the rarest and most valuable, and Z, the one with the highest amount of yellow.

CARLTON diamonds correspond to the letters G/H, in the near colorless range.
What most consumers are unaware of is the fact that diamonds can actually have colour. These fancy diamonds are very rare and, hence, extremely valuable. The most common are the yellow and brown diamonds, but they can also be found in gorgeous shades of red, purple and blue. These are so rare and expensive that above a certain weight we can find them in famous auction houses.


Diamonds are natural gems that form in nature at great temperatures and under enormous pressures, which makes it possible for gemmologists to find “impurities” in them called clarity characteristics. They help determine a gem’s quality and identity. Those characteristics also have a grading system designed by GIA, that uses the following nomenclature: F (Flawless), IF (Internally Flawless), VVS (Very Very Slightly Included); VS (Very Slightly Included); SI (Slightly Included) and I (Included). Flawless diamonds present no inclusions or flaws of any kind at 10x magnification and that makes them extremely valuable. So, if you have hear about a D(colour)/Flawless(clarity) diamond, you know you are in the presence of an extreme rarity; The “perfect” diamond.


A good cut is the human contribution to the beauty of a finished stone. When the diamond interacts with light, every angle and fact affect the amount of light that is reflected back to our eyes. An experienced craftsman can cut the stone having in mind the ideal proportions to enhance the scintillation of the finished gem. The cutting scale rates the diamond from Excellent to Poor.

Taking care of your Diamond

Most people know that diamonds are rated 10 in the Mohs scale, and that makes them the hardest gem on earth. But they are not indestructible. Especially, because the only thing that can scratch a diamond is another diamond. When buying diamonds, please be advised that they need to be regularly cleaned, as they especially attract grease. A very simple and safe procedure to remove grease is to use a soft toothbrush and warm, soapy water.

You should also have the stone setting verified every two years. CARLTON workshops are at your servisse for any advice and further repair, if needed.

Taking care of your Pearls

Pearls are organic gems that derive from living matter. They need care due to their fragile porous surface.

Skin care products, like moisturizers, perfumes, or any chemicals present in other products can damage their nacre, the natural shimmer of the pearl’s surface.

Because they are more fragile than the other gems, we advise you to keep them safe in their original boxes and separated from other pieces of jewellery. This way you can preserve that natural beauty that it’s its main feature and enjoy your pearls for many years.


Every CARLTON jewel comes with a certificate which guarantes its quality. Each of our pieces is carefully designed and crafted by specialized technicians and artisans using the best materials in its conception and development. We know jewellery and we want to share this passion with you.