For more than 35 years, Peter Gilder has tried to make the buying of an engagement ring a fun, and exciting experience. After all, it is one of the most important decisions we will ever make, and one we should enjoy, rather than fear! Knowing what you are spending your hard earned money on makes it easier to decide exactly which diamond is best suited to you. Only you can decide what you want to spend, but our role is to help you understand just what makes one diamond more valuable than another. Once armed with the information, deciding on a budget becomes a lot simpler.


The Earth has produced millions of diamonds, but the vast majority have microscopic internal imperfections, and only a very few are absolutely perfect.

It is this difference that we will explain in the simplest terms, and which will help you to understand why one diamond can cost many times
more than another which looks very similar.

To help us to explain we have broken down these characteristics into 4 main areas. Each area is described by a word starting with the letter C
and this is where the term the 4 C’s originates. Here’s your guide to understanding “the 4C’s”


This could also translate in to size, but quite simply the bigger the diamond the more valuable. Remember the rarity thing, there are fewer big diamonds than small diamonds. We measure the weight of a diamond in Carats and Points. 1 Carat weighs 100 points, just like Rands and Cents! Rarity!


This should actually be described as NO colour! The purest of colours is actually the one which seems to be almost invisible, this we call the “whitest” or most “colourless”. As the diamond exhibits a more yellowish or brownish tint, so the stone becomes less valuable. Why? Because there are fewer colourless diamonds than yellow or brown diamonds. Rarity!

We have given simple names to the colours. The most colourless or whitest of all diamonds is given the title of a colour D, and as the stone becomes less colourless, so we go from, D to E to F etc. all the way down the alphabet.

Things become a little tricky when the stone has such a strong (or vivid) yellowish or pinkish or greenish or blueish colour, that the alphabet plays no role. These we call “fancy coloured” diamonds and their prices can be as high as a colour D. Remember the rarity thing!


Every diamond has what we call natural inclusions or imperfections of some sort. So we have to have a cut off line of some sort to define the degree of these inclusions. With modern technology, we can magnify a stone to many hundreds of magnifications, so if the practised diamond grader cannot determine any internal inclusions of any sort under 10 X magnification, the stone is considered “Pure” or “Flawless”.

As the degree of imperfections increases so titles are assigned to the diamond.

FL (Flawless) VVS, (very, very small inclusions) VS (very small inclusion) SI (small inclusion) or I (Included or imperfect)

As we drop down the perfection list, so the stone becomes less valuable.
Why? Because there are fewer flawless diamonds than Imperfect diamonds.


Then there is cut, and this is mainly assigned to the proportions to which the diamond is polished.

The angles in which the facets are cut relative to one another, are critical in creating the scintillation or sparkle we see in a well cut or well-proportioned diamond.

A well cut or well-proportioned polished diamond is one that truly sparkles. It is these critical proportions which only highly skilled diamond polishers and graders can measure and which appear on the certificate which accompanies all our diamonds.

Again rarity plays a role as many diamonds are cut poorly in an attempt to maximise carat weight at the expense of all the other important factors.


The finished shape of the diamond is also referred to as the cut of the stone. This too can play a role in determining the value of the stone.



Although not one of the 4c’s, the industry has recently introduced the measurement of natural fluorescence which the stone exhibits when placed under ultra violet light, as a further method of determining the uniqueness of the diamond. More diamonds fluoresce than not.

The bottom line?

A 1 carat, D/Flawless, perfectly proportioned diamond with no fluorescence will cost somewhat more than a ½ carat, colour I/ VS1, badly cut stone, with high fluorescence. The trick is to find a balance between quality and price that you are happy with. We can help you with that!


here is a 5th C, and we believe this to be as important as the other 4. Confidence in the jeweller you are buying from, confidence in the advice you are given, and as important, confidence in the long term relationship with your jeweller once you have made your choice.

Let us assist by paying us a visit and let one of our diamond experts show you the Peter Gilder difference. It really is a lot of fun!!!