The better the proportions, the better the diamond handles light to create more sparkle. There are a number of shapes which diamonds traditionally take, depending on the original nature of the rough, uncut stone. It all comes down to what you like. The make of Diamond is often referred to as its cut, or as its proportion and common diamond shapes are brilliant round, heart, oval, marquise, pear, princess, and emerald. Of course some Diamond retailers simply say they have only fine makes and leave it at that.
Some jewellers sell very poor makes of diamonds everyday under the guise of bargains.
I always advise my clients fully before a purchase. The relationship between seller and buyer is probably one of the most important factors in buying the perfect Diamond. You need to be an expert and use specialized equipment to make sure a diamond is real. But be aware of the fact that some gas bubbles in cubic zirkonium may appear like inclusions if you do not look carefully.