How to Valuate a Diamond – 4C’s:
Today the fact is that very few people can distinguish between a good diamond and a bad one, they do not even know if what they are looking is a diamond at all or not. Cut, Colour, Clarity & Carat are four parameters to evaluate a Diamond known as “4 Cs”.
The proportions and finish grade of a diamond establish the quality of the cut. A good finish grade testifies to the workmanship of the diamond polisher. It refers to the symmetry of the facets and their overall finish. The best cut diamonds also have the right proportions between the different parts of the diamond. If these proportions are not optimal, the fire and brilliancy of the diamond are affected, and undesirable visual effects might occur.
The point of colour grading is to mark the degrees of grading from the whitest possible stone down to the yellowest which is still acceptable as being of gem quality. This is true when the diamond is viewed from the front and the eye confused by the spectrum colours. Lighting is vitally important, sunlight for example contains ultraviolet light which can cause the diamond being examined to fluorescence very slightly blue but enough to hide any tint of yellow.
Having ascertained a diamonds colour, the next step is to grade it according to clarity by assessing its degree of freedom from imperfections, clarity grading is straighter forward than colour grading, but arguable classifications can still arise. Inclusions are tiny crystals of other minerals that crystallized at same time as the diamond. The vast majority of diamonds have such inclusions, usually crystals of olivine and garnet.
Impurities & Defects in Diamonds: More information click here
The weight of a diamond is measured in carats. There are 5 carats as equal to 1 gram (142 carats to the ounce) and the carat is commonly divided into 100 cents (points). Diamonds of less than 1 carat in weight are known as pointers. A small portable chemical scale can be used to weigh diamonds to within a hundredth part of a carat. So many jewellers use electric balances.