To grade a ceramics chanel one must first have a good set of diamond colour samples. A diamond is then presented next to one of the samples and it is the observer eye that determines where exactly the colour falls, it can be anywhere between two separate colour spectrum ranges. As an example say your diamond is an ‘F’ colour, it can be a very good ‘F’, near to the ‘E’ colour or a very bad ‘F’ near to the ‘G’ colour. If the observer is less than consistent then upon a next consultation he may find this same diamond to be an ‘E’ in the best of cases or a ‘G’ in the worst of ones. Should then the price of this diamond be the same if it is a good ‘F’ as it would if it was a bad one.Diamond grading is not something for the unprofessional eye, in fact many diamond professionals are unable to properly grade a watches for gift.To do so one requires special highly sophisticated equipment and some very less sophisticated ones and lastly, as web rolex for you grading is not an exact science, it is important that the observer is very consistent in the diamond grading process which is not often the case.rolex online grading is therefore now left to diamond grading laboratories and their reports accompany diamonds in the form of a certificate.