The diamond industry has developed an internationally recognised and standardised benchmarking system. Any given diamond certificate is approved by three examination bodies, who objectively assess the attributes of the diamond under examination. A credible certificate records the observable characteristics of a diamond, for instance the shape, weight, cut, colour, clarity, polish, symmetry, etc., to determine the grade of the purchased diamond.
Currently, the more well-known and commonly used diamond certificates include:
The Leo Diamond® has partnered up with IGI to create the “Leo Diamond Certificate”, which is uniquely designed and first of its kind in the Asian region. In addition to showcasing the excellence of Leo diamonds, this independent certification further guarantees the quality of Leo’s diamonds.
- Description : Proof that the stone is a natural diamond.
- Shape and Cut : Describes the shape of the diamond.
- Weight : The weight of the diamond as measured in Carat.
- Measurements : Refers to the diameter of the diamond’s widest circumference, its smallest diameter and its depth (i.e. height).
- Clarity Grade : The clarity of a diamond is determined by the size, quantity, colour, positioning and other characteristics of internal inclusions and other imperfections. The six clarity grades range from FL, IF, VVS, VS, SI and I.
- Color Grade : Refers to the natural colour of the diamond, and is classified into several grades, the highest being D, followed by E, F, … to Z. The closer to colourless a diamond is, the higher its value. Coloured diamonds are graded according to a different system.
- Fluorescence : When exposed to ultraviolet light, some diamonds emit a visible glow, usually blue in colour. The strength of fluorescence is classified into the following grades: None, Faint, Medium, Strong or Very Strong.
- Polish、Symmetry、Proportion : Together, these factors determine the quality of a diamond’s cut, ranging from Excellent, Very Good, Good, Fair to Poor.
- Table Diameter、Crown Height、Pavilion Depth : These factors’ relative ratios are used to judge a diamond’s proportion, which is one factor that determines the quality of the cut.
- Culet Size : The culet is the area at the bottom of the pavilion of a diamond. Pointed (as in no culet) to medium-sized culets are ideal.
- Girdle Thickness : Refers to the widest part of a diamond, which divides it into two halves - the crown at the top and the pavilion at the bottom. Thin to slightly thick girdles are ideal.
- Plot of Internal and External Inclusions : Both internal and external inclusions can be plotted on cross-sections of a diamond’s top face and bottom, so that their size and positioning can be recorded.