2010年7月28日星期三

Solitaire Diamond Rings: Certification and Grading

For fancies, the smallest diameter (width as opposed to length) is used. For example, if the table measures 5.7 mm, and the total diameter of the diamond measures 10.0 mm, then the table percentage is 57%.FinishThe finish of a diamond includes two separate factors: the polish and symmetry. The finish is a very good indicator of the care taken by the craftsman to make the diamond as beautiful as possible. This is one of the most contributing factors to the cut grade and cut quality of a diamond. We do not recommend engagement solitaire diamond rings with Poor or Fair grading for polish or finish.Most people just write or say it as a 1.6 ratio.Depth PercentageDepth percentage refers to the ratio of the average depth of the diamond (from table to culet) as compared with the average diameter (which is used as the 100% figure for all diamond dimensions). The ranges that are commonly considered best for each shape vary slightly, but we will just give the basic dimensions for rounds here: Ideal = 58 – 60%Excellent = 60.1 – 62%Good = 62 – 64%Fair = 64 – 66%Poor = over 66% or under 57%Table PercentageTable percentage is the ratio of the table width as compared to the total width of the diamond. For rounds, the largest diameter is used.