Diamond Grading - The 4 Cs
The 4 Cs refer to Carat, Cut, Colour and Clarity. They determine the grading of diamonds and all have an impact on the value of a diamond.Carat
The weight of a diamond is measured in Carats (Caratage) and carats are divided into points. The price of a diamond will rise proportionately to the size of the stone thus larger diamonds are very rare and have a greater value per carat. Thus a diamond weighing 1 carat doesn’t cost twice as much as a diamond weighing ½ carat and a one-carat diamond will cost much more than a 95 pointer.
Carat is often confused with size even though it is actually a measure of weight. One carat is equivalent to 200 milligrams, or 0,2 grams. One carat is divided into 100 “points.” A .75 carat diamond is the same as a 75-points or 3/4 carat diamond.
The word carat is taken from the perfectly matched carob seeds that were once used in ancient times to balance scales by merchants.
Naturally, size is sought after, but overall quality is the determining factor in the end. The balance of size and quality makes up much of the artistic nuance of a professional gemologist or gem cutter. It is the cutter's job to produce a gorgeous lavish diamond, while giving the consumer the highest Carat Weight for their money.
Clarity
Clarity refers to the presence of any marks on and within the stone. Some of these occur naturally and some occur because of the stress put upon the stone during the mining process. All diamonds are graded based on their appearance, which means the presence or absence of blemishes and inclusions. They are graded on a scale that ranges from F (flawless) to I (inclusions). There are very few flawless diamonds found in nature, thus these diamonds are much more valuable.
|
Grade |
Characteristics |
|
FLAWLESS/IF |
Internally flawless |
|
VVS1 - VVS2 |
Very,very slightly included |
| VS1 - VS2 | Very slightly included |
|
SI1, SI2 |
Slightly included |
|
I1, I2, I3 |
Inclusions mainly visible under a microscope of 10x magnification as well as some to the naked eye |
Colour
The absence of Colour gives a diamond its great value. Starting on a grading scale with D for colourless, the rarest and most valuable diamond, to Z. There are also diamonds, such as naturally yellow or pink diamonds, which can be valued for their colour.
There are 2 categories of diamonds in respect to colour:
1. White Diamonds - These are diamonds falling within GIA's D to Z colour grading scale, traditionally used for engagement rings and fine jewellery.
2. Fancy Natural Colored Diamonds - These are diamonds with faint to vivid saturations of hues such as blue, yellow, or pink, frequently used for fashion jewellery.
White diamonds graded D through F are the most valuable and desirable because of their rarity. Diamonds graded G through I, do not have any colour that can be detected by the untrained eye.
Diamonds graded J through M, have colour that can often be minimised or almost completely hidden by carefully selecting the right setting or mounting style and colour. For example, yellow metals will hide traces of colour in a white diamond, while white metals will enhance it.
With fancy colour diamonds, however, there is a large difference. Here, the importance is the purity and richness of the diamond's colour. Yellow is the most commonly-occurring fancy colour. Red and green diamonds are extremely rare. The price of fancy coloured diamonds depends on several factors: The particular hue of the diamond (the rarer the colour, the greater the cost); the richness or saturation of the colour (ranging from very light to light to intense to vivid); and the purity of the colour (i.e. whether the color is bright and clear, or 'muddied' by the presence of other colour-causing trace elements).
Cut
Many people confuse Cut with the shape of a diamond. The cut refers to the facets in the diamond and enables it to make the best use of light. The more light that is let into a diamond the more it will sparkle. The majority of the diamonds on the market are cut round with a full 58 facets.
The shape of a diamond, however, is largely a matter of personal preference
