Grading diamonds is all about valuation Carat, Clarity, Colour and Cut by a standard method. By weighing the diamond on a calibrated scale it’s easy to establish the carats. To get an insight on the clarity you have to draw all physical characteristics of the diamond using symbols in green (external) and red (internal) in a diagram. The physical characteristics must be determined with a 10x magnifying glass, but we used the microscope at first. When using a loupe you have to hold the diamond with a stone tweezer in one hand and the loupe in the other hand. It takes a lot of practise to be able to draw the correct symbol on the right spot in the diagram. Using a microscope with a higher magnification makes it easier to determine what you see and to draw the symbols because you can keep the same steady view. Colour is the most difficult part. You have to compare the diamond you are grading with a set of nine reference stones. The differences are so small that it takes an awful lot of practise. The cut was more easily for me because designing sculptures and jewellery is all about proportions. But expressing proportions in % is not as straight forward as might seem. All the values of the determination are put in a final report. When doing it correctly you can recognise the graded diamond by the diagram of physical characteristics.