Our love affair with diamonds is enduring. Nothing makes a statement like a gorgeous diamond glinting in a lovely setting worn as a ring, earrings, or pendant.
Of all diamonds sold, round brilliants account for 75 percent. The attraction is the perfect circular shape and the exceptional brilliance and fire created by the facets produced by the diamond cutter.
But as diamonds come in a variety of shapes, why are round brilliant cut diamonds the most popular, but also, the most expensive? You pay a higher price per carat for round diamonds compared to other shapes.
The Difference Between Diamond Shape and Diamond Cut
Interestingly, the judgment and valuation of a stone do not primarily consider the diamond shape. Diamonds are judged by the four Cs
- Carat
- Cut
- Clarity
- Color
As a purchaser, you should also consider a fifth C – certification. It would be foolhardy to buy a diamond or a piece of diamond jewelry without it being accompanied by a GIA Certificate (a report on a diamond’s four Cs issued by the Gemological Institute of America).
When it comes to shape, it’s important to understand that shape is not the same as cut. The shape refers to the form and geometry of the stone. The common diamond shapes are
- Round brilliant
- Emerald
- Oval
- Pear
- Marquise
- Baguette
- Radiant
- Heart
- Princess
- Asscher
- Cushion
- Trillion
While a rough diamond must be cut to form a shape, the cut refers to the stone’s facets and proportions. Whatever the shape, it is the cut that gives diamonds their brilliance and fire.
The Diamond Cut
There are two types of cut:
- Brilliant cut
- Step cut
The characteristic of brilliant-cut gemstones is the triangular or kite-shaped facets that radiate from the center. The facets of a step-cut stone are long and narrow, arranged in parallel rows to produce a “hall of mirrors” effect.
The facets on step-cut diamonds are larger than those of brilliant-cut stones and generally, the diamond is a square or rectangle.
The shapes that have a brilliant-cut are:
- Round brilliant
- Oval
- Pear
- Marquise
- Radiant
- Heart
- Princess
- Cushion
- Trillion
The shapes with a step-cut are:
- Emerald
- Asscher
- Baguette
Some of the fancy-shaped diamonds are easier to cut and this can result in stones that have more sparkle than others. But there is also the issue that some cuts can make a stone more fragile. It is commonly agreed that princess cut diamonds and marquise cut diamonds are the most fragile.
Round cuts are considered the most robust than fancy cuts because there are no pointed or sharp edges that could be prone to chipping or damage. Round cuts are also easier to set in a piece of jewelry.
Having established the difference between shape and cut, let’s look at cut in greater detail
The Diamond Cutting Process
Every beautiful diamond begins as a rough stone. The resulting cut grade, carat weight, shape, color grade, and brilliance are all down to the skill and craftsmanship of the diamond cutter.
Generally, natural uncut diamonds are roughly an octahedron shape (a polyhedron with eight faces, twelve edges, and six vertices).
To begin, the cutter will examine the rough stone to determine its potential carat weight and decide on the best shape. This will inform the cut before the cutting and polishing process begins. The aim will be to maximize the diamond’s brilliance by optimizing the fire, scintillation, and brilliance.
Usually, an octahedron rough stone will be cut into two rounded gems. A rough stone that is not an octahedron will be cut and polished into a fancy shape diamond.
But, if the natural geometry lends to the round shape and they are the most popular diamond shape, why do round brilliant diamonds cost more?
Why Are Round Brilliant Cut Diamonds More Expensive?
Round diamonds are in high demand, even though they are up to 35 percent more expensive than fancy shape diamonds.
The fancy shapes can be huge and rather magnificent, yet it is still the round shape that people want in their diamond engagement ring. The diamond solitaire is still the most popular in every piece of jewelry from earrings to rings to pendants.
This high demand might lead you to think that the price should be lower but it isn’t the case.
The primary reason for round being the most expensive diamond shape is that a large amount of the rough stone is lost during the cutting and polishing process. To achieve the fire and brilliance characteristic of the round shape, more of the original is lost than when cutting a fancy shape.
A rough diamond can be more easily manipulated to accommodate the irregularity of fancy shapes. More time, attention to detail, precision, and skill is required to achieve a perfectly symmetrical cut round diamond.
As well as the lost raw material, no other diamond shape can match the fire and sparkle of a round shape. This cut quality is the second contributory factor to diamond prices.
Offsetting this, however, is that it is easier to minimize any flaws or inclusions in the round-cut diamond.
As has already been mentioned, the diamond shape that has the most brilliance, fire, and sparkle is the round brilliant cut. It’s human nature to want the best, especially if you are investing a significant amount of money. The cut quality is significant but it is usually the way a diamond flashes fire when you look at it that most attract the buyer, hence the high diamond for round diamonds.
If you want to save money on buying a diamond and not spend on the most expensive diamond cut, look at how shape influences price.
Because of lower demand, trillion, pear-shaped and marquise cut diamonds command lower prices than other cuts.
Princess cut diamonds are also more affordable per carat weight than round brilliants because less of the raw stone is lost in the cutting process.
Cushion cuts and oval cut diamonds are also cheaper for the same reason.
You also need to know that there are factors that will inflate the price of fancy shape diamonds. For example, emerald cut diamonds may be more expensive because particular skill is needed in cutting to avoid the dullness that the elongated facets can create. As another example, true Royal Asscher diamonds also command a higher price tag because, being a proprietary signature cut, they are rare.
A cutter and a jeweler will both understand a great deal more about the quality of a diamond than a buyer.
Buyers may well be informed of the four Cs but most will not know that there are sub-categories or grades within each C.
Carat – the carat weight of a diamond will always contribute to the price tag. The stone’s GIA certificate will state the carat weight.
Cut – as discussed above, cut is reflected in price by how much of the rough stone is lost during cutting and polishing.
Color – diamonds come in a wider range of colors than most people imagine, from brilliant white through yellow, blue, and pink to brown. The deeper and more intense the color, the more expensive the diamond will be. Due to their rarity, red diamonds are the most expensive. Colors also have a grading scale.
Clarity – clarity is, too, assessed on a scale. A diamond’s clarity is graded according to its inclusions. The inclusions are looked at in terms of size, nature (type), number, location, and relief.
So relating these back to round brilliant cut diamonds …
There is much more leeway when it comes to clarity and color than with fancy shape diamonds. Because the cut itself produces a greater intensity of color and brilliance than in fancy shapes, lower grades in diamond color and clarity can still look far superior.
Lower graded round brilliants will be priced lower than higher-graded stones, but in terms of price per carat weight, you may get a better round brilliant stone than a comparable fancy stone of the same carat weight.
The cut also means that a round brilliant diamond may also appear “eye clean”. The sparkle and fire may hide any imperfections to the naked eye, even if the grade is recorded at the lower end of the scale in the GIA certificate because the imperfections are visible under proper inspection.
Another reason for the round brilliant being the most popular diamond shape is its versatility. It is the easiest to adapt to multiple settings so many designs are possible. It can be a white gold ring with a simple setting of a solitaire held by prongs or a round brilliant can be a center stone around which other stones are set.
There are far more pre-made settings available for round diamonds than for other fancy shapes. Some like cushion diamonds, radiant cut diamonds, or an oval-shaped diamond often have to be “forced” into a setting, which then makes them more vulnerable to loss and damage.
The Takeaway
Round brilliant-cut diamonds are the most expensive because of the raw material lost and the intricacy of the cutting process.
Most fancy shape diamonds are unable to match the fire, scintillation, and brilliance of a round shape diamond.
At the end of the day, however, the most important thing is to find a diamond you love at the price you want to pay that is either in a setting you love or able to fit the design you desire.
