The 4Cs of Diamonds

When it comes to evaluate diamonds you will inevitably stumble over the 4Cs: Carat weight, Colour, Clarity and Cut. This system was established back in the 1940s by the GIA (Gemological Institute of America) and are now the most commonly used four factors to evaluate and price diamonds. However, they should be considered as a guideline of a diamond's characteristic rather than making a definite statement of a diamond's overall beauty and qualities. A clear and flawless diamond can depreciate a lot in its value if the cut does not bring out its full beauty, a quality that is difficult to measure. Beauty is in the eye of the beholder and when you buy a diamond you should examine it and judge for yourself whether you find it visually appealing or rather dull and boring.

To give you a quick overview of what the 4Cs mean:

Carat Weight: As the name suggests, this is the weight of the diamond, measured in Carats. The carat is an old unit, and legend has it that it was derived from the weight of carob seeds. The modern standard sets the weight of 1 carat to equal 1/5 of a gram (=0.2g). The carat is divided by 100 points with each point equalling 2mg (=0.002g). Weights of all gemstones are expressed in carats. It should not be confused with the measurement of gold purity, which confusingly is also expressed in carats. The heavier a diamond is and all other factors being equal, the more valuable it is (although exceptions do exist as a trend in fashion may result in a higher demand of smaller diamonds and in turn drives prices for the lower weight stones up).

Colour: The colour of the diamond is an important factor when it comes to your purchase decision. Yellowish diamonds are valued lower than diamonds with no or minimal colour. Colours are expressed with a letter ranging from 'D' to 'Z'. Diamonds graded D or E are colourless, F-H have a subtle hint of yellow, I-K have a faint but noticeable yellow colour to them and anything above this increases the colour of the diamond and with the stronger colour comes a lower price. Colourless diamonds with a D or E grading are rare and thus command the highest prices. The letters A-C are not in use as they have been reserved when the system was first established in case diamonds of even better grades than D are ever to be found. So far, these letters have never been used or probably never will be.

Clarity: This term deals with how "clean" the diamond is, both internally as well as its surface. Ideally, a diamond has no inclusions or blemishes but such diamonds are very rare in nature. The less imperfections a diamond has, the higher its value. Diamonds with serious inclusions not only look poor but threatens the durability and life of the stone itself. A clarity rating is given by a qualified grader using a loupe with 10x magnification.

Cut: Diamonds come in various cuts, with the most popular one being round or brilliant cut. Other common cuts are oval, princess cut, heart shape or fancy cut. A round cut brings out most of the brilliance of a diamond but what cut is used depends on current market conditions and popularity and whether a particular cut can preserve some weight of the rough stone, i.e. making the polished gemstone heavier than for example using a traditional round cut. The cut quality is an important factor to consider when buying diamonds as a poor cut makes an otherwise flawless diamond look dull, whereas an excellent cut and finish can maximise a diamond's beauty and making it more desirable.

Some other factors you should consider are brilliance and life of a diamond or any other gemstone, even though they are less commonly mentioned. Brilliance can be measured by the amount of dark areas the crystal shows when viewed under overhead lighting or a single light source. The less dark areas are visible, the better the cut and quality of the stone are. A poorly cut diamond lacks of lustre and exhibits a greater amount of dark areas, resulting in a dull look.

How much "life" a diamond has is the least scientifically measurable factor and depends much on objective perception. A stone with favourable characteristics and a good finish will sparkle and show lots of life, whereas a heavily included diamond or one with wrong cutting proportions will look dull and boring. Some cutters compromise on cut quality in order to increase the diamond's weight, but this in turn lowers the per-carat weight. Often, a smaller but well finished diamond is the better choice, exhibiting a much higher per-carat weight.

The 4Cs are a good starting point for choosing the right diamond for you but they should not be given priority over your personal impression of a given stone. If you find a VS1 stone that is more appealing to you than a VVS2 one, then you should go with the former. Not only will you be happier with your purchase, but it most likely saves you money too, all other factors being equal. When it comes to buying diamonds, you should always be willing to some compromises on certain aspects and not get carried away with grades. You will find moving a grade in colour or clarity up or down will not make an enormous difference and if you are lucky you walk away with a great stone at a discounted price.

Enjoy the experience!

Where to go from here?

Now that you are equipped with the basics of the 4Cs of Diamonds, you can dig deeper into the different subjects. Below is a list of relevant articles that we have prepared for you. Click on the links for further reading: