A diamond is born - Diamantschleiferei Michael Bonke

When a so-called lot (a gemstone package with a specific number of diamonds) is through withthe cutting process, it is boiled, weighed, counted once again and it then goes to the grading-roomfor grading. In our plant, grading is done only by women. In our experience, women are moreconsistent graders than men.Depending on the grader’s state of mind, the grading is sometimes strict and sometimes notas strict. A diamond grader must obviously try to keep these mood swings at a minimum whenevaluating. The stones are first sieved. Small brilliants are not classified and sold as per theweight, but as per the sieve size.Thus, the following categories are customary ininternational trade:Sieve size- 6½ brilliants of 0.003 to 0.02 ct+ 6½ - 11 brilliants of 0.025 to 0.07 ct+ 11 - 14 brilliants of 0.075 to 0.135 ctWeight categories are used to classify stones ofsieve sizes larger than 14.After the sieving, the stones are first graded asper the colour and then as per the clarity.