Valuing Diamonds

Valuing Diamonds
The quality and value of diamonds are measured by four characteristics known as the 4C's. The 4C's relate to a diamond's cut, colour, clarity and carat weight. The quality of a diamond is measured by its cut, colour and clarity. The carat weight measures the size of the diamond. Of all the 4C's, cut is the characteristic directly influenced by man; colour, clarity and carat weight are all dictated by nature.A diamond in its natural, uncut state is described as a "rough diamond". Its natural appearance so resembles a glass pebble that most people would pass it by without a second glance. It is the skill of the diamond cutter that unlocks the brilliance for which diamonds are renowned. If two identical diamonds are placed side by side and one is less brilliant and fiery than the other, the fault lies in the cutting. Such a stone cannot demand as high a price as a well-cut diamond. It is important to distinguish between cut and shape. Some of the more popular shapes of diamonds include Round Brilliant, Oval, Marquise, Pear, Heart and Emerald. Within each of these shapes, however, it is the cut that determines the quality of the stone. For example, most diamonds are cut with 58 facets, regardless of their shape.A diamond's colour is one of the most important factors in determining its value. The nearer a white diamond is to being absolutely colourless, the more rare and valuable it is. The graduations in colour are so subtle that intricate international grading scales have been devised. Diamonds are graded into categories defined by letters. The colour range from exceptional whites (categories D, E and F) to tinted colours (categories M to Z). The best way to pinpoint a diamond's true colour is to place it next to another diamond that has previously been graded. There are also fancy coloured diamonds and these are graded according to their intensity of colour, not lack of it. There are a variety of reasons for diamonds to be coloured. The most common causes, or suggested causes, for the colours yellow, green, blue, brown and pink are described below.Yellow: When nitrogen combines with the diamond crystals during the formation stage it causes a surplus electron in the bonding. This surplus electron absorbs blue light, thus giving off a yellow colour. Yellow diamonds also occur when aggregates of three nitrogens combine and cause surplus bond.Blue: The elements of boron may also be substituted within a diamond during its formation. Boron absorbs red light, hence in the absence of nitrogen, diamonds containing boron are blue in colour. An example of a diamond containing boron is the famous Blue Hope diamond. Diamonds containing boron also exhibit unusual electrical properties and are semi-conductive in nature. Hydrogen is