Depends on whether the stone is round or fancy cut. Well made round stones should have a thickness of 0.5% to 5% of total depth of stone.
“Small” indicates size of culet only and does not affect proportions of stone until the size reaches “medium” and larger.
This is because faceting in brilliant cuts maximizes the balance between life (brilliance) and fire (dispersion), faceting in emerald cut diamonds does not.
There is more flexibility in cutting of fancy shapes. Fancy cuts have recommended ratios of length to width.
The present market demand is higher for rounds (brilliants) than emerald cuts; but this can always depending on market conditions.
The brilliant cut maximizes the balance between life (brilliance) and fire (dispersion); because cut is a question of taste and all cuts are beautiful in their own way. Brilliant cut has a 58-facet arrangement that radiates from the centre of the stone towards the girdle, and has triangular facets.
Diamonds with the same carat weight can vary enormously in their style of cutting. Cut depends on the nature of the rough, the polisher, and the different proportions of cut that are sought in various markets, since not all markets have the same preference.
It is important to understand the difference between the cut, that is the shape of the diamond, which is entirely dependent on your taste and the skill of the diamond cutter in producing the finished.
No, the number of facets can vary for heart shapes and pear shapes. Emeralds have the same number of facets.
This is dependent on what the market demands dictate.
No, although, some registered cuts claim to provide grater brilliance and scintillation, however, as is the case with all diamonds. Beauty is in the eyes of the beholder.
The ideal proportion for a heart shape is 1:1 length to width ratio.
It is worth pointing out that a diamond that has been badly cut will not have the same fire, brilliance, scintillation and light as that in a diamond that has been well cut to maximize these qualities.