The most important aspect of diamond cutting, our most intuitive visual effect can judge the quality of diamonds. The following points should be noted in the evaluation method: 1. Facets of diamonds: Generally, the table tops and facets of diamonds are straight without warping. If a good diamond is placed on a table with straight edges and corners, the reflected image will not be deformed, while imitation or poorly cut diamond will have the effect of warping the table. 2. The edges and corners of the diamond: The edges and corners of the diamond should be straight and sharp. For a diamond ring cut in the shape of a standard round diamond, three or more edges should strictly intersect at one point and form an acute angle, and two facets should also strictly intersect at an edge line. However, imitations similar to diamonds often have smooth edges and corners because of their low hardness and poor cutting. 3. Diamond waistline: The waistline of a standard round diamond is usually unpolished after rough grinding. This unsmooth waistline is called saccharification effect. Therefore, the saccharified waistline is a typical cutting and grinding feature of diamonds, which is waxy and reflective. However, most of the diamonds with poor quality have polished waistlines, and grinding lines can be seen under the microscope.