How to Buy a Diamond: 4C’s Diamond Buying Guide by Charles Ziegler

by Mr Charles Ziegler, president of Galeries du Diamant

Buying a diamond is a big and important decision, so I hope to explain to you what's behind the famous 4Cs. It's all about cut, clarity, color and carats, and where better to come than Antwerp, the worlds most important Diamond Center where all the world’s diamonds come at least once.

The first 'C' to take into consideration when you choose a diamond is the cut. Now, the cut determines the shape of the diamond as well as its brilliance, because different cuts have differing facets, and it's these facets that give the diamond its sparkle. Think of facets like reflective surfaces that shine light through the diamond. The better the diamond is cut – the better it will look.

There are many different diamond cuts for you to choose from, so let me tell you my thoughts on each of them. The round brilliant cut is the most classic and popular cut for an engagement ring, and I think you can understand why; it's because it gives a nice iconic shape on the hand, and it has this fabulous brilliance, thanks to its 57 facets.

The oval shape is in fact a variation of the brilliant cut, so it's got lots of brilliance and sparkle like the round one, but it suits small hands somehow better.

The pear shape is a really elegant cut I think, and it works beautifully on petite hands. Because it's got the pointed end, it has the effect of elongating the fingers. It gained a lot of popularity in Asia in the past few years.

My favorite has to be the cushion cut, it has nice combination of a very precise, modern cut, but with a sort of old-fashioned air about it.

I love the emerald cut, because it's very, very traditional. It's got these elongated, clean lines, which make it have a sort of deep shine as opposed to a brighter sparkle, and the emerald cut suits all hands and works great with long fingers!

Once you've made up your mind about the shape of the diamond, it's really important that you make sure that you buy a good-quality cut, because it's the precision of the cut that determines how much fire you will get from a diamond. Galeries du Diamant will only sell cuts that are from excellent to very good, which means that you are making the very most of that investment.

Our next 'C' is for clarity, and this refers to how clean or transparent the diamond is. It goes a lot more than just skin deep. To determine how clear a diamond is, you'll need a jeweler’s loop with ten times magnification. Bear in mind, any grading information that you find on a diamond certificate refers to what is visible with ten times magnification.

The imperfections that naturally occur in a diamond have two names, so if they're inside the diamond, they're called inclusions, and if they're on the surface, they're called blemishes, so you need to look out for those two different types. Inclusions are more visible in some cuts than others, and the most forgiving cut for inclusions is the cushion cut that has a lot of facets, whereas the emerald is quite the opposite, and its long, clean lines that shine right into the heart of the diamond mean that there is no room for any flaws.

The clarity of a diamond is graded on a scale, from imperfect to flawless; the most desirable. This is of course determined by how many imperfections are within that diamond. After flawless comes VVS, which stands for very, very slightly included, and then just after that is VS, which stands for very slightly included followed by SI – slightly included.

Another capital 'C' to consider when buying a diamond is color, and if it's a white diamond, ironically what you're looking for is total absence of color. The top grading for a white diamond is D, and then it goes down alphabetically right to Z.

How do we grade a diamond for color? The way to go is to look at it upside down, so that eliminates the brilliance factor, against white paper, and then to check that against a set of master stones. Only an expert can be precise while determining a color of a diamond.

If you look to buy a solitaire diamond ring, the general recommendation, and that of Galeries du Diamant as well, is to not go below H, because any point below that then you do start to get a slightly tinted colour.

Not to be forgotten is another vital 'C', and that is of course carat weight. Carat refers to the weight of the stone, where one carat is one fifth of a gram. You don't need me to tell you that a bigger diamond is more valuable than a small diamond, but the larger diamonds are also much more rare, so this means that a three-carat diamond is many times more valuable than a one-carat diamond; it isn't simply three times more valuable.

Now what about the size of your diamond? Not all diamond cuts look the same size even if they are the same carat weight, and a round brilliant cut is the one that outperforms the others; it looks bigger than most of similar-carat shapes. If you're going for the big look on the finger, the brilliant cut will do then trick.

Now, for a solitaire diamond engagement ring, what you really want to have is that wow factor so don’t go below 0,3 carats. Carat and size is not everything, so you always have to balance that with the other three Cs, and come to the ideal choice that works just right for you. Always remember that a well-cut diamond will always look better than a lesser-quality cut, even if it's the same carat weight.

At Galeries du Diamant Antwerp or Paris shop, you will see the most amazing range of sizes and cuts of diamonds, all of them top quality, knowing that they have been cut by the best in the business.

For generations, Galeries du Diamant has been involved in the diamond business, and it is one of the few companies that can claim to be involved in the life of a diamond, right through from buying the rough, to cutting and polishing, and of course setting the diamond in its own workshops. This means that Galeries du Diamant are involved in every single stage of what makes a diamond special.

In Antwerp we handle some of the most exceptional stones. I'm talking about those enormous, hugely valuable, multi-million-dollar diamonds that make the headlines, and it's this immersion in the world of diamonds that I think shines through in every single one of our engagement rings, right through to the smallest wedding band.

To start your journey of buying a diamond, you really can't do much better than coming to Antwerp.

Charles Ziegler, President of Galeries du Diamant

Mr. Ziegler is the diamond expert since 40 years and the third generation of Antwerp’s Ziegler family. He is running Galeries du Diamant in Paris and Antwerp to get the worlds best diamonds for you.