Diamond Cut Meaning (Ultimate Guide)

Diamond Cut Meaning (Ultimate Guide)

What does diamond cut mean? Why is it important to know this terminology if you are looking to buy jewelry? Read our diamond cut meaning guide to find out.

Want to know what a diamond cut is and whether it has an effect on the price?

Good, you have come to the right place!

In this detailed jewelry guide, you will get answers on questions like:

  • What is a diamond cut?
  • Is a diamond-cut important?
  • Does a diamond-cut affect its price
  • What are the different kinds of diamond cuts
  • The best buying advice when considering the cut

Unlike clarity, how a diamond has been cut greatly affects the fire and brilliance. For example, a flat cut and deep cut diamond lose a lot of brilliance when reflected in UV rays.

Diamonds are assessed for their quality using the 4Cs. In our opinion, Cut is the most important C out of the 4. Continue reading to get to know more about diamond cuts and how to make the best buy.

A diamond’s cut determines how much the stone will sparkle, albeit with brilliance being its natural feature. Diamonds that have been precisely cut let light pass through the top and the back, making the stone shine bright. Some of the commonest cuts you have probably heard of include emerald, cushion, and princess among others.

Diamond cut is not simply giving the stone a defined shape, it is more than that. The process is so complicated that the final appearance has a direct impact on the price and value of the diamond. We shall take you through a detailed description of the different diamond cuts explain the grades and quality too. You will also learn the importance of a diamond’s cut in maximizing its optical properties.

What is “Diamond Cut?”

Round, pears, oval are some of the cut names that you will hear most of the time. Although the names sound like shapes, they do not directly mean the diamond shape but cut. It is simply a coincidence that the cut represents the shape. A diamond cut is also used to explain some diamond properties like symmetry and polish. A simple look at the diamond’s beauty should distinguish an excellent cut diamond from a poor cut. The beauty of a diamond stone is seen from its brilliance, scintillation, and fire: all these make up the optical properties of diamonds and any other gemstones.

Brilliance in diamonds refers to how much light is passing through the diamond. A diamond with a perfect cut allows a lot of light to pass in and out. Scintillation refers to how light and sparkling dark facets are arranged when the diamond is exposed to a conventional light. When diamond stones are placed in a dark environment, the resulting rainbow effect is what gemologists call “fire”.

Difference Between Diamond Cut and Shape

In diamonds, cut refers to the dimensions used in the diamond that determine the stone’s level of shine. Generally, the more precise or perfect the cut is, the more light passes through resulting in better fire, scintillation, and brilliance. A diamond’s shape is its general appearance normally determined by how the 2D edges are outlined.

Effect of Diamond’s Cut on Price

How beautiful or valuable a diamond depends on the quality and precision of the cut.

Gemologists aim at producing equal facets so that the diamond can achieve the utmost sparkle. For example, a brilliant round cut diamond must have each of the 33 facets in equal proportions to prevent light from leaking.

Diamonds that have no fire and brilliance have lower values than average. A diamond that is poorly cut will look dull even if it is big with high carat weight. All 4Cs of diamond quality assessment are important but the cut affects the beauty of the diamond. If you desire to have the best quality cut diamond, you may be forced to compromise on GIA clarity or color.

Types of Diamond Cuts

One of the main factors you would consider when looking for the best diamond online is cut. The following are the common cuts that you will find in online jewelry stores.

Here you can see various types of cuts at JamesAllen.com.

1. Cushion Cut

A cushion cut diamond is denoted by its large facets and round edges. This design gives it high brilliance. The cushion cut is normally confused with other cuts depending on how visible the round edges are.

GUIDE: Cushion Cut Diamond Guide

2. Round Cut

Round cut diamonds are the most common especially in top-tier engagement rings. Over the years, this has been the cut that diamond traders use to bring out all the sparkle. Most diamonds lie in this cut especially if you are looking for particular components.

GUIDE: Round Cut Diamonds Guide

3. Princess Cut

Princess cut diamonds look like squares, they have very sharp corners. When viewed from any angle, princess cut diamonds have a blazing brilliance.

GUIDE: Princess Cut Diamond Guide

4. Emerald Cut

There are no two emerald cut diamonds that are similar in terms of the length-width ratio, diamonds are different. An emerald cut diamond features rectangular facets and look more like an open table. The good thing with emerald cuts is that you can see any defects or inclusions that the diamond may have especially if you go for SI2 or worse grades.

GUIDE: Emerald Cut Diamond Guide

5. Marquise Cut

Marquise cut diamonds normally look like a shield, they are large and long. When wearing a marquise cut diamond ring, your finger will appear long and skinny.

6. Pear Cut

A pear cut diamond looks similar to a teardrop. This cut is notoriously known for the bow-tie effect: you should look out for this when buying rings with pear cuts. Like a marquise cut, a pear cut will also make your finger look skinny.

Diamond-Cut Grades

Diamond cut grades are developed by GIA. GIA grading is by far the most recognized independent diamond grading institute in the world. When shopping for diamonds in terms of cut grades, you are advised to rely on GIA’s grades, even industry experts depend on this entity.

Read below to know how the Gemological Institute of America (GIA) grades diamond cuts


This is the best grade of diamond cut which has proportions meant to give the highest fire and brilliance. The facets are so perfect that all the light passing through the diamond is reflected. AGS’s Ideal Cuts are the equivalent of GIA’s excellent cut.

Some companies choose to call these cuts Excellent Ideal Cuts or Super Ideal Cuts or another acronym preceding the phrase Ideal Cut.

GUIDE: Are Excellent Ideal Cuts Worth The Extra Money?

Super ideal cuts or excellent ideal cuts are grades that are assigned by the jeweler and not any recognized grading institutes like GIA and AGS. They are normally used for marketing purposes and may not reflect the actual diamond grade. In most cases, they are far much beyond the excellent cut grade and exhibit high sparkles. Astor Ideal is one such diamond cut from Blue Nile that is allegedly one of the 15 out of the 10,000 diamonds that have this cut.

Very Good

A good amount of light that passes through a very good cut diamond is always reflected through the table. Generally, this cut has very good brilliance and fire. In fact, the sparkle of very good diamonds is identical to that of excellent cuts when seen by the naked eye.


A good cut diamond reflects just enough light for the eyes to tolerate through the table. The levels of brilliance and fire can be withstood by the eye. The price of such diamonds is a bit low because of the brilliance level.


This diamond grade does not reflect most of the light that passes through it. This means that the level of fire and brilliance is greatly interfered with. These are not the best diamond pieces to be used as a centerpiece. They can best be used as side stones.


Just from the word poor, you can tell that such a diamond grade does not sparkle at all, has no scintillation or fire on it. This happens because the facets are not proportionate to each other. The light that enters the diamond goes through the bottom.

How Diamond Cut Quality is Determined

The cut quality of a diamond is determined by proportion, polish, and symmetry. Every one of these factors affects the brilliance, fire, and scintillation of the diamond. Let’s look at how each of them plays out.


The proportion of a stone is the relationship between the shape, angle, and facet size. These traits are related to the internal properties of the diamond. When a diamond stone is well proportioned, you will notice that each of the facets has been inclined to an angle that reflects the most light.


Cutting and polishing a stone is quite a vigorous process. Polish refers to how smooth the facets look after the process of cutting and polishing is done. For a diamond to have a glazed appearance, thorough polishing must be done after the cutting is complete. How smooth the facet is tells how brilliant the stone is. Although polishing does not affect the diamond’s brilliance, it does not mean that good polishing should not be done.


A symmetrical diamond has facets that balance perfectly and with proper alignments. Symmetry is achieved by looking at the crown to check whether it conforms to the pavilion ad by checking the culet‘s position in relation to the table. Not so good sparkle is brought about by facets that have not been properly balanced. To get the perfect facet balance, gemologists use a 10x microscope to examine a diamond’s symmetry.

Our Diamond Cut Recommendation

By now, you already know that diamond cut supersedes its clarity, color, or carat when looking for the best diamond to buy. When shopping around for diamond rings, be extra cautious about those described as the super ideal cut, excellent ideal cut, or anything in that line of description.

Why should you?

There is no much difference in the cut grade between the ideal/excellent cut and the super/excellent ideal cuts. These are just terms used to entice customers. Before you get so excited about these cuts, make it a point to check the AGS or GIA grading report. AGS will report their best grade as Ideal Cuts while GIA reports its best as Excellent Cut. Do not solely rely on the retailers grading report as this may mislead you.

Apart from depending on GIA or AGS grading reports, diligently do your homework. Examine different stone proportions, looking at different angles and measurements. Although it may seem like a huge task, it will save you a lot when buying diamonds. For online jewelry shopping, I would recommend you buy from James Allen; you will get a chance to view the diamond in 20x magnification.

All in all, the cut carries most of the weight when shopping for a diamond. It not only hides defects but hides secondary colors too and increases brilliance making your diamond extra shiny.

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