To maximize returns on this rare and yet valuable resource, the Corporation evaluates rough and polished diamonds before exportation. The Corporation evaluates rough diamonds from all rough diamond producers and polished diamonds from local manufacturers. Evaluation is a process of assigning a value to a parcel of diamonds using specific criteria of diamond sorting to match price quoted parameters and factoring other market factors (developments) that have a bearing on the value of the product. Diamond sorting is done on the basis of 4 parameters often referred to as 4Cs:
- Size often referred to as carat size of the diamonds.
- Quality/Clarity – the degree of inclusions in the diamond as observed using the naked eye and 10X loupe (magnifying glass). We talk of quality when dealing with rough diamonds and clarity when dealing with cut diamonds. Higher magnifications can also be used for a closer analysis, though the 10X loupe is the internationally recognised basis for quality/clarity grading.
- Shape or Cut which defines the outline of the diamonds. The parameter is spoken of as shape when rough diamonds are involved. It is referred to as cut when cut diamonds are involved.
- Colour which is the remnant refractive or reflective electromagnetic wavelength the human eye perceives when light passes through or is reflected from the diamonds.
Quoted prices are released based on the sorting parameters described above by established research companies such as IDEX, Rapaport, Ajediam, etc. Other market factors such the response of the market to a specific production, political factors, quality of cut, the brand of the grading laboratory (especially on polished diamonds), etc have a bearing on the price that could be realized and are also factored in.