Understanding Diamond Cut

In the GIA diamond grading scale, cut diamond refers to the type and quality of a diamond’s cut, specifically its proportions and symmetry. It is important to note that the diamond cut does not refer to a diamond’s shape (Pear Shape, Heart Shape, Round Shape, etc.). The diamond cut directly affects the diamond quality and impacts its overall look. It also determines a diamond’s ability to capture and reflect light, thereby determining how much brilliance and fire it exhibits. Many people actually consider cut grade to be the most important factor when choosing a diamond because it’s essentially what determines how much a diamond shines.

Diamond Cut Grades

Since the establishment of the diamond cut chart and standardized diamond cut grade criteria, diamond cut quality is now described as the following cut grade types, according to how the diamond produces white light reflection and maximum brilliance:

Elements Affecting the Cut Quality

The GIA (Gemological Institute of America) has developed a diamond cut grade system used in the diamond business, that can be broken into seven components, on which diamond certificates are based.

1. Weight ratio – The appearance of the size of a diamond relative to its same carat weight
2. Durability – The possibility of chipping or breaking due to an excessively thin girdle
3. Polish – How smooth or scratched the flat surface is after the polishing process
4. Symmetry – How well balanced and aligned the facets are, with the objective of producing optimal facet angles
5. Brightness – Brightness created from white colored light reflecting from the surface and inside of the diamond
6. Fire – The dispersion of light into colors of the visible spectrum
7. Scintillation – The pattern of the light and dark areas of the diamond and the flashes of light produced when a diamond is moved in the light

Diamond cutting requires a high level of craftsmanship and must strike the right balance between stone size and cut quality to come up with well cut diamonds. You can find a beautiful selection of high-quality diamonds at reputable dealers like James Allen and Blue Nile.

Does Cut Grade Influence the Price?

The cut of a diamond impacts its overall appearance and brilliance as well as polish and symmetry and the greatest amount of brilliance can only be found in a diamond that has been exceptionally cut. In its rough state, a diamond can actually look dull in appearance. There are also additional costs for the skilled labor required to craft an ideal cut diamond. So yes, a diamond’s cut is definitely an important feature that impacts a diamond’s beauty, along with its price.

In all cases, a diamond that is cut well and ranks higher on the cut chart will appear bigger and more radiant in comparison to a diamond that is cut poorly. For many obvious reasons, people would prefer to have a diamond with a high cut grade as it is not only appraised higher but will look brighter and more sparkly. However, there are still some that would buy not as high cut grade diamonds to match their budget.

For people who are looking for something a little more cost-effective, we would advise purchasing a diamond that is lower in color grades rather than cut quality because as mentioned before, having a good quality cut will make your diamond appear more attractive and radiant.

However, your final buying decision should still be based on your or your partner’s personal preference.

James Allen offers four different diamond cut grades, two of which are Excellent or Ideal. Their TrueHearts^TM diamonds are a type of Excellent cut. If you need more information or would like to request a specific cut grade or shape, feel free to contact them or visit their website for more details.

Diamond Cuts

Round Cut

When people are asked to describe a diamond shape, most will reply “round” and indeed this is regarded as a classic design, particularly popular with engagement rings. Although strictly speaking a round diamond could be almost any cut, the most famous and prominent is the round brilliant diamond cut. The brilliant-cut is noted for featuring either 57 or 58 facets which give the diamond its famous sparkle. The round brilliant cut is what some would say how cut diamonds should look like.

Princess Cut

A relatively recent creation, the modern princess-cut features distinctive pointed corners. Traditionally square, some princess-cut diamonds are slightly rectangular in shape, though this may be difficult for the untrained eye to detect. The princess cut is one of the most popular cuts and can have up to 76 small facets. The classic prong is the best setting for princess cut as it allows more light to pass through the stone and uses less metal than other settings. Princess cut diamonds typically cost less per carat compared to round diamonds.

Cushion Cut

Widely popular in the late 19th century, antique-style cushion-cut diamonds have recently experienced a resurgence in popularity. Influenced by the old mine cut, which featured rounded corners and large facets, the cushion cut diamonds have a soft, romantic appearance. Ranging from square to rectangular, height to length ratio is an important factor when considering a cushion-cut diamond. Clarity is also important with this cut, as the larger facets highlight the diamond’s clarity.

Asscher Cut

The modern Asscher cut can be described as a square emerald cut; both have a pavilion cut with rectangular facets. Asscher-cut diamonds feature step facets and cropped corners that make them appear octagonal when viewed from above and offering brilliance along with its signature appeal. Designed to emphasize clarity, the Asscher cut allows you to see all the way through the diamond. There are two types of Asscher Cuts. There’s the standard Asscher Cut diamond and there’s the Royal Asscher Cut. Both were created by the Royal Asscher company. Asscher diamonds usually have 58 facets, the same as a round brilliant. The arrangement of these facets gives it a vintage “hall of mirrors” look.

Emerald Cut

Originally developed for the cutting of emeralds, the emerald cut is prized for its clean lines rather than its brilliance. A large table and the step cuts on the pavilion give emerald-cut diamonds a unique look that really accentuates clarity. Similar to oval diamonds, the length to width ratio of emerald-cut diamonds can vary. A length-to-width ratio of 1.40-1.50 ratio is ideal for a classic emerald-cut shape usually consists of 57 facets. Emerald cut diamond shapes go well with solitaire and simple pave settings and are perfect for three-stone settings.

Marquise Cut

With curved edges and two pointed ends, the unusual marquise-cut is a modified brilliant cut. With its long, narrow boat-shape, marquise cuts have the largest crown surface area of any diamond shape, giving the illusion of a larger stone. The shape of marquise diamonds is also ideal for elongating the fingers of the wearer.

Oval Cut

An oval-cut diamond combines the brilliant faceting of round diamonds with an elegant elongated shape. Oval diamond cuts actually give diamonds the appearance of being larger than they actually are. It can also make the wearer’s fingers appear longer and slimmer. Traditional oval diamonds have a length to width ratio between 1.35 and 1.50.

Radiant Cut

Like the emerald-cut, a radiant-cut diamond has straight sides and trimmed corners. However, their faceting gives them a much greater level of brilliance, resulting in a very sparkly diamond. Radiant cut diamonds use a hybrid cutting style that combines the clean lines of square cuts with the faceting of the round brilliant cut. The shape of radiant-cut diamonds can range from square to rectangular. Radiant cut diamonds are one of the most affordable cuts because the cutting process uses a larger percentage of the original diamond rough, so very little goes to waste.

Pear Cut

Featuring a single tapered point, the pear cut diamond is reminiscent of a water droplet. Worn with the tip pointing either up or down the finger, the elongated pear-shape subtly slims the fingers. This is a vintage style diamond cut and is known for high sparkle. The dimensions of pear-shaped diamonds vary, though the most traditional ratio is between 1.45 and 1.75. Pear shape diamonds are versatile as they can be perfect as a center stone or used as lovely diamond accents.

Heart Cut

A heart-shaped diamond is both a symbolic and unique choice for an engagement ring. A modified round brilliant cut, heart shaped diamonds are generally worn as solitaire rings or pendants and are made up of between 56 to 58 facets giving this stone high brilliance.

How cuts affect light refraction:

Though we already touched on the topic of cut styles and shapes, we have yet to talk about cuts in terms of quality. This relates more to the proportions of the cut and the skill of the diamond cutter behind it. The diamond’s width and diamond’s depth affect the way light is reflected, which in turn would affect its brilliance and optical appeal.

Deep Cut:

When the diamond is cut in such a way that the pavilion depth is far too large, it is considered a deep cut. This means that the light won’t reflect back (upwards), stealing away from the diamond’s shine, quality and price. Thus, it is a poor cut.

Shallow Cut:

A shallow cut is seen when the pavilion depth is cut far too small in proportion to the diamond width. This, same as the deep cut, causes poor light reflection and affects the jewel’s price, quality and brilliance and becomes another poor cut.

Fine Cut:

The fine cut is one of two commonly acceptable cuts. Its proportions are close enough to the ideal cut that it displays brilliance and light reflection that might look perfect to the naked eye. The girdle size is a common difference between the fine and ideal cuts, as well as the crown size, at least in proportion to the rest of the diamond.

Ideal Cut:

An ideal cut is when a diamond has perfect proportions and light reflection. Diamonds of an ideal cut have the most shine and brilliance, with light reflected directly back at the viewer’s eyes. This is the cut to go for every time. Check out James Allen’s beautiful selection of ideal cut True Hearts^TM diamonds here.

How Diamond Shapes Affect Face-up Size

There are 10 most popular diamond shapes – round, princess, cushion, emerald, pear, marquise, asscher, radiant and heart. The round shape cut has 58 facets, thus, its ability to reflect light gives it unrivalled sparkle factor.

There are also so-called fancy shapes to distinguish from the popular round and round brilliant cut. The popular fancy shaped diamonds are the oval cut, princess cut and cushion cut. The princess cut is the fancy cut diamond most popularly requested for diamond engagement rings.

Fancy cut diamonds are not as expensive than the round cut diamonds, because of the elongated cut. A marquise cut diamond, or oval cut or pear cut, can look bigger than the other shapes despite the same carat weight because these have a large surface area depth percentage relative to the diamond cut proportions. The fancy shape of the rectangular cushion cut, radiant and princess cuts also have the same effect.

Why are round diamonds popular?

The round brilliant diamond cut produces the most, best, highest sparkle. A well cut round diamond’s brilliance and dispersion of all the light makes it a most impressive diamond engagement ring! Despite not having a large face-up area, its sparkle intensity makes it appear much bigger. That is why this cut and shape is still the most expensive. Shopping for an engagement ring? Check out these stunning collections from James Allen and Blue Nile!

Frequently Asked Questions