Diamond shape vs cut / Diamond cut guide: Though mostly the term diamond cut and diamond shape is used interchangeably but when it comes for diamonds they are two unalike things. The shape of the diamond means how it appears due to its outline like heart shaped or a round or any other fancy shape which just by looking we get to know that a round diamond is circular and heart shaped looks like a heart. The cut of a diamond indicates the types of facets or their arrangement, symmetry, measurements in cutting for any same weight and these affects the finish and reflection of diamond in same shape like a round diamond can be cut shallow or deep in hieght but the shape will finally appear as it is that is round.
The cut comprises the arrangement of facets, the manner in which it is cut, the symmetry, place of facets on the rock. Suppose a round cut diamond can be a rose cut diamond which are shallow in height and a totally different variety of cut then a round brilliant cut which emits the maximum amount of brilliance, for example a pear modified brilliant cut diamond which employes the same cutting style as a brilliant round cut diamond with a pavilion crown table but shape is unalike; other cuts are step cut which is extensively used in emerald cut forming a hall of frame effect and this same stone can be made shallow or deep retaining the same octagon shape shap. Any cut and polished diamonds may even remain round or oval without having any single facet on it.
So here we understood that cuts is the way or style in which facets in any shapes are arranged and shape is just the outline or boundary in which all the modifications will happen though it may be a princess cut diamond or a square emerald sugarloaf both are square so shape may be same with different cut and cut quality which affects the price of diamonds the most expensive and demanded being the brilliant cut in round or cushion and princess cuts.
Any same brilliant cut can be categorized according to its quality like good cut, very good cut diamond, or excellent cut diamond and it is judged on the basis of the amount of brilliance it is giving and how ideal the proportions are, it should be not too deep or too shallow, the table surface area should be in a proper ratio with that of crown and so on. Fluorescence. polish and origin of the diamond also affects its shine and luster followed by types of inclusions like cloud etc.
A diamond cut in a particular fashion with many facets to bring out exceptional brilliance; this cutting may be applied to various shapes like pear but is a synonym with rounds.
ROUND CUT - The most common of shapes is the round brilliant cut diamonds and is the most demanded and selling diamond of all other shapes. Around 75% of the diamonds selling worldwide are round cut diamonds as the facet arrangement linked to each other in them has the potential to produce maximum brilliance / shine then any other shape and cut and thus enjoys advantage with its counterparts. Almost all the melee diamonds used in the jewelry are round brilliant cut melees.
PRINCESS CUT - The princess cut diamond is the second highest preferred shape in diamonds as cushion. They were created first near year 1980, it has parallel 4 sides and pointed corners (square shape). They are easy to handle due to shape with edges and manufacture cut and polish, these gives excellent brilliance / luster.
MARQUIS CUT - This is also a modified cut diamond similar to rugby football tape pointed on 2 sides and bulged from the mid section like a leaf. the marquis diamond has the biggest surface area as to weight. The marquise cut also as oval cut gives illusion of being bigger then weight compared to other shapes like princess or cushion.
OVAL CUT - This is again a brilliant cut diamond and is cut like virtually the round brilliant cut so it has the same kind of brilliance as the round cut diamond but it may have this advantage as an elongated version of round to create an illusion as marquise cut to depict size and weight to be bigger than other shapes like round or cushion of same weight.
CUSHION CUT - A cushion shape diamond is amongst the centuries old cutting styles used to happen of diamonds. It is a kind of modified square cut with rounded ends. The diamonds which are traded as old mine cuts now are mostly cushions. Now with more refinement in the cuts and proportions the demand of this cut has increased.
PEAR CUT - Pear shape diamond is a mix of round and marquis cut diamond with tapered point on one side and round on another, they being brilliant cut show good firing in the stone. The pear shaped diamond needs to be cut with proper symmetry as the tapered point should remain in the center of the round curve of another side, The curved part should be uniformly arched on both side to accelerate towards the taper point otherwise it will no longer remain a pear modified brilliant cut diamond. In diamond trading the prices of all fancy shape diamonds are generally decided as per the price chart of pear shape in Rapaport chart.
EMERALD CUT - The emerald cut diamond is a unique cut which gives a distinct type of look to the diamond, in this instead of the brilliance of a brilliant cut step cutting is done which depicts a hall in a frame effect as the stone is moved it displays a change in the shades from dark to light visible on each step or plains of the cutting. It is more famous in precious gemstone emerald and is the same way done in natural diamonds.
ASSCHER CUT DIAMOND -It is a modified type of emerald cut and is first discovered in Holland by asscher brothers in 1902. It has similar step facets as in emerald cut diamond but is not elongated as an emerald cut but is in square shape with a higher crown and smaller table, the table is always kept small compared to other flat facets, so this type of faceted combination gives the stone more firing or brilliance.
RADIANT CUT - Its a octagon shape diamond which is completely cut as a brilliant cut diamond with lots of facetes at crown and pavilion and it has a ability to give more firing/luster then other of its counterparts like cushion or princess cut diamond as it is something in between those two. It is second most shiny diamond after round brilliant and looks well in setting with both rounded and square cornered diamond in jewelry.
HEART CUT - Heart shape diamond is really a unique and different shape from the rest a heart modified cut diamonds signifies love and is used as pendants in most of the jewelry, it is cut like a shape of a heart, but these diamonds if below 0.40ct may not be a good choice as after setting in prongs its shape is not clearly visible in that little size.
Now all these cuts have a unique look for every type of color shades in diamonds like an emerald cut diamond if has very light tint of yellow or brown it will be easily visible and same shade if happens in asscher cut or round brilliant cut from the table the very light shade almost disappeares. Minor inner inclusions tend to less appear in a round brilliant cut then a rose cut or a oval cut diamond so color, inclusions and luster even depends on kind of cut and shape followed by the quality of polish, now there are even more new technology used in cutting of diamond facets like extra facets are given to the brilliant cut diamonds for extra luster.
Most of the diamond rough / uncut diamonds mined worldwide is cut and polished in India. Diamond miners like Al Rosa and De Beers in South Africa auction the rough diamond which is then cut and polished in India to form a finished diamond to be used in jewelry.