The weight of a diamond is measured in carats; a carat is equivalent to 0.2 of a gram. The chart below does not show the actual size of the diamond.
Diamonds are found within a range of colours, the rarest being colourless or fancy such as green, blue and red. A letter is assigned to a colour grade..
Clarity grading should take place under favourable lighting conditions by a skilled grader using a 10x corrected loupe.
IF – Internally Flawless describes a diamond with no internal characteristics but which may have minor blemishes on the surface.
VVS1 & VVS2 – describes a diamond with Very Very Slight Inclusions.
VS1 & VS2 – describes a diamond with Very Slight Inclusions.
SI1, SI2 & SI3 – describes a diamond that is Slightly Included and are usually obvious when viewed under the conditions mentioned above.
I1, I2 & I3 – describes a diamond that has inclusions which are visible with the naked eye.
Proportions/Cut – Well proportioned diamonds exhibit three different properties: brilliance, dispersion and scintillation. As light strikes a diamond’s surface, it will either reflect off the table of a polished stone or enter the diamond. The light that is reflected is known as the diamond’s brilliance – the flash of white light one sees when looking at a stone. As light travels through a stone, some of the light rays are separated into flashes of colour. This is known as dispersion. The result of dispersion—the separation of white light into its spectral colours — is known as fire. Scintillation is flashes of colour that are visible as an observer moves a diamond back and forth.
Polish – this refers to the final polish of each facet. The polish influences how well light is able to pass through a diamond. It is a very important attribute in determining a diamond’s overall brilliance.
Symmetry – Symmetry refers to the exactness of the shape and arrangement of facets in a diamond. Although to the naked eye finish features only have a tiny effect on appearance, symmetry is significant. In diamonds that have low clarity grades, symmetry is less important, but in diamonds with very high clarity grades, symmetry is very important.