The international colour grading system uses the letters, D to Z, to denote a colour, where D is colourless and the depth of colour increases down the scale to Z.

Colour grade is assigned by comparison to a master set of colour grading stones that each act as the borderline between two colour grades. D to Z grades are a range of tones of colour where one merges into the next.

There may be very little distinguishable difference between two diamonds that are close to each other on the scale, such as a low F colour and a high G colour.


Comments are closed.

%d bloggers like this: