Diamond Cutting Works
5 C’s and Diamond Grading :
Carat, Clarity, Colour, Cut & Cost
As with all precious stones, the weight of a diamond is expressed in carats. The word carat originated in a natural unit of weight: the seeds of the carob tree. Diamonds were traditionally weighed against these seeds until the system was standardised and one carat was fixed at 0.2 grams (one fifth of a gram). One carat is divided into 100 “points” so that a diamond of 25 points is described as quarter of a carat or 0.25 carats. Here are some other examples that show the approximate size of the diamonds in question.
Almost all diamonds contain minute traces of non-crystallised carbon or small non-diamond crystals. Most are not discernible to the naked eye and require magnification to become apparent. Called inclusions, they are natures fingerprint and make every diamond quite unique. However the fewer there are, the rarer the stone will be. Clarity, therefore, is the term that is used to indicate the extent to which the diamond you purchase is free of these natural phenomena. There are four major grading systems for classifying diamonds – GIA, CIBJO, IDC and Scan D.N. – and an international standard (ISO) is soon to be. At present a stone is termed flawless by the GIA if it is without surface characteristics or internal inclusions: other systems use the term Loupe Clean which equates to both flawless and internally flawless. Grades then gradually descend and are compatible.
Most diamonds appear to be colourless, some contain tinges of brown or yellow. “Fancies,which are rare stones, vary in colours such as green, blue or pink.
4 . CUT
The precision with which your diamond is cut will determine its brilliance, its sparkle and ultimately beauty. The cut is the only aspect of your diamond which is determined by the craftsman. The more skilled the craftsman, the more you are assured that your diamond has been cut to bring out it’s ultimate beauty.
All of the C’s are important factors when it comes to determining the cost of a Diamond. When you want to buy a Diamond keep in mind that a smaller diamond with a good cut is often a better investment than a bigger diamond with a poorer cut.
HOW A DIAMOND HANDLES LIGHT
1. It is the cut that enables a diamond to make the best use of light. When a diamond is cut to good proportions, light is reflected from one facet to another and then dispersed through the crown or the top of the stone.
2. If the cut is too deep, some light escapes through the opposite side of the pavilion or bottom.
3. If the cut is too shallow, light escapes through the pavilion or bottom before it can be reflected.