hi Reece
The passage below will tell you all you need for the differences of quality and clarity.
Premium Quality - Colour H/I and Clarity I1-2
Colour H-I: A white diamond with no easily noticeable colour tint to the naked eye. Only once compared to higher colour qualities can you notice a difference.
Clarity I1-2: The "I" stands for "inclusions". Any imperfections in the diamond can only be noticed if you look very closely at the stone (within 6 inches). With smaller diamonds, imperfections become even harder to notice.
Conclusion: H-I/I1/2 quality represents great value and is a higher quality than you will find on most high streets!.
H/Si Quality - Colour H and Clarity Si
Colour H: A white diamond with no easily noticeable colour tint to the naked eye. Only compared to much higher colour qualities are differences noticeable.
Clarity Si: An abbreviation for "small inclusions". Certainly on diamonds under 0.50 carat, imperfections in the diamond are not noticeable to the unaided eye. Only once under a jeweller's high powered magnifying glass, can inclusions be detected.
Conclusion: H/Si quality is our usual recommendation. White diamonds with no visible inclusions, you can't go wrong!
G/Vs Quality - Colour G and Clarity Vs
Colour G: A bright white diamond. Expert knowledge needed to identify any colour tint ie. essentially colourless.
Clarity Vs: An abbreviation for "very small". Referring to the inclusions, any imperfection can only be seen with expert knowledge and with the use of a high powered jeweller's loupe (magnifying glass).
Conclusion: G/Vs quality is the connoisseurs choice. If you like to appreciate the finer things in life, this is the choice for you.
If all this seems daunting, call us on 0845 084 1200 and we will point you in the right direction.
I hope this helps.