most rare and valuable, and therefore the most desired diamonds, are
those that appear “colourless”.
Diamonds are graded alphabetically on a colour scale from “D”
which is totally colourless down to “Z” which is light
yellow/brownish in colour. The
whiter the diamond (or the more colourless) the less light that is
inhibited and the more brilliant the stone becomes.
table below shows a diamonds colour rating.
||K - R
||S - Z