Diamonds are graded on their Cut, Colour, Clarity & Carat Weight.
Diamonds come in many different cuts & sizes. The modern cut for round diamonds is the brilliant cut which is designed to maximise the light reflected off the facets giving exceptional brilliance.
D ~ Absolutely Colourless: Extremely rare diamond with no trace of colour.
E-F ~ Colourless: Appears colourless. Indistinguishable from D grade to the naked eye.
G-H ~ Near Colourless: Very faint tint but appears colourless to the naked eye.
I-J ~ Near Colourless: Faint tint only apparent when compared with higher quality stones.
FL-IF ~ Flawless/Internally Flawless. No inclusions visible even under 10x magnification
VVS1-VVS2 ~ Very very slightly included. Inclusions only just detectable under 10x magnification
VS1-VS2 ~ Very slightly included. Some inclusions, invisible to the naked eye
SI1-SI2 ~ Slightly included. Inclusions may be visible to the naked eye.
I1-I3 ~ Included. Inclusions are visible to the naked eye (sometimes noted as P1-3)
Carat Weight ~
The carat weight is basically the weight of the diamond ~ the higher the carat, the rarer the diamond. Weight gives you a rough idea of size but it isn’t exactly equivalent as the quality of the cut can also make a difference.