There are 4 different diamond cut gradings which you can purchase from any Jeweller.
I need to emphasise that when buying a diamond, that the cut is one of the most important things. The beauty of the diamond depends more on cut then any other factor. A well cut diamond can have a slightly lower colour (G-H) or clarity (SI1-SI2) and still look quite beautiful, due to its superior ability to create sparkle and brilliance.
Some Jewellers may differentiate the name for the type of cut, however the following are based on Bluenile.com one of the leading online Jewellery specialists.
Signature Ideal cut (only at Bluenile.com): Top 1% of diamond quality – with precise proportions, polish and symmetry – allowing the diamond to reflect even more light than the standard Ideal cut.
Ideal cut: Highest cut grade. Its proportions produce a beautiful balance of fire and sparkle in a diamond.
Very Good cut: Very slightly less measurable fire or sparkle than an ideal cut diamond, at a more affordable price.
Good cut: Quality at a lower price than a very good cut, still producing a beautiful diamond for the budget-minded.