“Square cut or pear shaped…These rocks don’t lose their shape.” Marilyn Monroe’s famous line from Diamonds are a Girl’s Best Friend is undoubtedly true, but the relationship between diamond shapes and diamond cuts is much more complicated than a simple song lyric.
Diamond shape simply refers to the shape of the stone itself, such as round, oval, pear, heart, etc., but cut refers to a diamond’s proportions, symmetry and polish. Of all the Four Cs (color, clarity, cut, and carat), cut is the most important factor in the overall beauty of a diamond.
While there are basically only two ways to cut facets into a rough diamond (brilliant and step), the “cut grade” of a diamond includes a rating of the diamond’s brilliance (the brightness created by white light reflections from the inside and the surface of the diamond), scintillation (sparkling flashes of black and white as the diamond moves), and fire (refracted light that appears as dispersed color).
When a rough diamond is cut into its final shape, some of the diamond is lost to waste. The dilemma for the cutter is how to maximize the carat weight of the finished stone without compromising the brilliance. A diamond cut that is too shallow or too deep might increase the final carat weight, or yield, at the expense of the diamond’s brilliance. A poorly cut stone might be larger, but dull and lifeless.
In the following article we’ll be concerned mostly with popular diamond shapes, remembering that different shapes are cut to different proportions and specifications, and will reflect light in their own unique ways.
Diamond Shapes: Round Cut
Round cut diamonds have always been the most popular diamond shape, and for good reason. Due to the physics of light and its interaction with the facets of the stone, the brilliant-cut round diamond is simply better at returning light, maximizing the diamond’s potential brilliance.
In his thesis “Diamond Design: A Study of the Reflection and Refraction of Light in Diamond” published in 1919, Marcel Tolkowsky scientifically analyzed the ideal proportions for maximizing light return and dispersion.
Though Tolkowsky’s original specifications have been slightly modified over time, the very best brilliant-cut round diamonds still have 58 facets, (57 when there is no culet, or small facet at the base of the stone), and incredibly specific proportions of table, depth, and crown angle.
Round diamonds are more expensive per carat than fancy shapes not only because of high demand for them, but because more rough stone is lost during the cutting process than in most fancy shapes. Due to their unsurpassed brilliance, round cut diamonds account for approximately 75% of all diamonds sold.
Diamond Shapes: Princess Cut
The princess cut diamond is the most popular of the fancy diamond shapes, second only to the round cut. Originally created in the 1960s, the princess cut was popularized in the early 1980s and is now a common choice for many engagement rings.
The princess cut is square, or slightly rectangular, and even though the crown is 10% smaller than a round cut diamond, it will actually appear larger than a round cut diamond of the same carat weight due to a larger corner to corner measurement.
And because less of the rough diamond is lost when creating the princess cut, the price per carat is lower than round cut diamonds as well.
The fire and brilliance of a princess cut diamond is second only to the round cut, making it a great combination of unique shape, value, and appearance.
Diamond Shapes: Radiant Cut
Radiant cut diamonds are a square cut with cropped corners. They first became popular in the 1980s.
Featuring an intricate 70 facet cut, radiant diamonds live up to their name as they are excellent reflectors of light, and make a great choice for those who appreciate the brilliance of a round diamond and the elegance of an asscher or emerald cut.
Because of their many facets, radiant cut diamonds tend to intensify the color of the stone, making them a great choice for fancy color diamonds.
Diamond Shapes: Emerald Cut
The rectangular emerald cut was originally intended for emeralds, and when used for diamonds creates an interesting effect.
The step cut pavillion and large, open table combine to create a hall-of-mirrors effect, and while nowhere near as brilliant as a round cut, the long lines of the emerald cut produce dramatic flashes of light.
Because of its large, open table, an emerald cut diamond highlights the diamond’s clarity above all, and makes any inclusions easier to see.
Diamond Shapes: Asscher Cut
Originally created by the Asscher brothers in 1902, the Asscher cut is a square cut with large, steep facets that peaked in popularity in the 1920s.
Thanks in part to refinements that gave this cut more brilliance, Asscher cut diamonds began to make a comeback in 2002.
Modern Asscher cut diamonds are similar to emerald cuts, but feature a higher crown and smaller table, and will appear to have concentric squares when viewed from above.
Diamond Shapes: Oval Cut
Created in the 1960s, oval cut diamonds are actually a kind of modified brilliant-cut round diamond, and have the kind of brilliance one expects from a round diamond.
There is no ideal ratio of length to width with this shape, but longer ovals lend themselves to settings with other stones, and can appear larger than they actually are.
Another advantage of the elongated shape is that it tends to make the finger of the wearer appear longer and slimmer.
Diamond Shapes: Marquise Cut
The marquise shape is another modified brilliant-cut, but in the distinctive shape of a football, with sharp points at either end.
Because marquise diamonds are narrow and long, they appear larger than they actually are. Carat for carat, they have the largest crown surface area of any diamond shape, making them a great choice for those trying to maximize the perceived size of the diamond.
Diamond Shapes: Pear Cut
The pear shape is round on one end and marquise shaped on the other–a simple combination of the two cuts forming a teardrop shape.
When worn as rings, pear shaped diamonds are always worn with the point toward the hand of the wearer. Symmetry is critically important with this shape–the point of the diamond should line up perfectly with the apex of the rounded end.
Like oval diamonds, there is no ideal length to width ratio, and narrower shapes make the fingers of the wearer look longer and slimmer.
Diamond Shapes: Cushion Cut
This classic diamond shape combines a square cut with rounded corners, and was the most popular shape diamond for well over a century before the rise of the round cut. Cushion cuts are known for delivering better fire than other cuts, though their overall brilliance can’t compete with a round diamond.
Refinements to the original cushion cut have resulted in much greater brilliance in modern versions, making them a popular combination of an antique feel with a modern light return. Standard proportions vary greatly with this cut, so personal taste will ultimately inform which diamond is right for you.
Diamond Estate Jewelry Buyers Purchases all shapes and cuts of diamonds worth upwards to $250,000. If you have a large carat diamond ring or necklace which you would like to sell for a generous cash offer, please contact us today for a free diamond appraisal and immediate cash offer.