What Is Diamond Cut Quality?

Last updated on September 1, 2024

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When it comes to precious stones arguably diamonds are the very top of the heap. Forged in immense heat and pressure miles below the earth's surface over thousands of years these lumps of essentially carbon can become amazing gemstones.

These gems look great when set into various types of jewelry including broaches, necklaces or even a diamond engagement ring. Depending on their quality and cut these diamonds can be truly stunning offering a sparkle or fire that can be almost hypnotizing.

The difficulty with diamonds however is that you could perform the most perfect job cutting a diamond but if the gem's natural quality is poor it will not be of value. Diamond value is dependent on the so-called 4 C’s: cut, carat, color and clarity.

In today's article we are going to look at the cut quality aspect of diamonds. Just how much does the cut quality actually affect the value of a diamond and why is it so important?

What Is Diamond Cut Quality?

We often refer to the shape that a diamond has been fashioned into as its cut but we also use the term to refer to the quality of the job performed by the diamond cutter themselves. Arguably the cut quality may be the most important factor in determining the value of a diamond.

One of the 4 C’s, cut quality is important to how well the diamond reflects light which is in itself a major aspect of a white diamond. Without a good cut to the diamond you will not get the maximum brilliance and fire from the piece.

The intention is to have all cuts be perfect so they reflect light in the most efficient and pleasing ways. It should sparkle and in the right light even seem to be ablaze with light. If the cut quality is lacking the light transmission may be weak and you get poor brilliance and a disappointing stone.

Ideally a diamond should capture light through its base and sides and then direct that out through the top of the gem. Poor cutting can allow the light to escape at the wrong places dulling the sparkling effect through the top of the diamond.

According to professional diamond graders there are four main cut quality levels: Ideal, Very Good, Good and Fair. Some companies do have their own proprietary grades which claim to be of higher quality than the highest quality but this is essentially just how the world of retail works.

You will see cuts such as True Hearts (James Allen), A Cut Above (Whiteflash) and Astor (Blue Nile). These are sales techniques to boost their best quality gems and to charge a little more for them. It works as well so why wouldn’t they use it?

What Diamond Grade Should You Buy?

Well I don’t know what is in your bank account and how much of what is in there you can spend on a diamond. Therefore the first piece of advice to give you is to set yourself a budget and know what you want from your diamond.

If you are looking for maximum sparkle you are going to want at least Very Good cut quality, a diamond close to colorless and one with very good clarity. These combined can really rack up the price so you may need to offset that with a smaller diamond.

That said if size is important to you then you need to consider more conservative standards for your diamond's quality. A good cut quality is perfectly acceptable in most cases and will offer you better value for money.

You must remember though that heavily colored white diamonds with noticeable flaws will have an impact on the gem's brilliance.

Diamond Cut Pricing

We played around with James Allen’s diamond search engine to find one carat, round brilliant cut diamonds with H color grade and a clarity of VVS2. We then checked the prices in the various cut quality ranges they offer. The results are below.

• True Hearts: $7,650 (only one diamond available with these specifications)
• Ideal: $4,440 - $7,950 (over 200 listings)
• Very Good: $4,760 - $6,650 (78 listings)
• Good: $4,950 - $6,450 (5 Listings)

We should point out that James Allen does not list any Fair quality diamonds. They only deal in gems that are Good or higher.

So looking at the prices above you will see some level of decrease in general prices as you get to lower cut quality levels. This is a hard variable to truly prove as each diamond is unique and retailers will vary prices even on seemingly identical diamonds for reasons they alone quantify.

The Cuts Explained

It is important to note that cut quality is only graded on round brilliant and princess cut diamonds. The other so-called fancy shapes do not have cut quality grading performed on them. Therefore the following sections explaining the cut grades refer just to round brilliant and princess cut diamonds that have been graded by an independent jeweler.

Ideal Cut

These cuts have been done with the utmost precision and an eye towards excellence. The diamonds have had facets cut in the perfect way to show off the maximum possible brilliance of the gemstone. The ideal cut is exactly what it claims to be, the ideal way to cut the diamond.

Very Good Cut

Sometimes diamond cutting experts will try to get more size out of a diamond but this can come at a cost. Proportions may not be quite as perfect and the result may be a slight but barely noticeable decrease in light brilliance.

These are still very well cut diamonds but they just do not quite classify as ideal or excellent due to some slight proportion and symmetry issues.

Good Cut

When it comes to value for money the Good Cut is probably the most desirable. You want the quality but your wallet is not loving the price tag. Good cuts again are a little lesser than very good and this will be due to trying to maximize weight and losing some of the accuracy of cuts. Realistically with today's laser cutting technology there is little excuse for lower quality work other than deliberate attempts to maximize size over cut quality.

Fair Cut

Diamonds with Fair Cut ratings you will probably notice are on the larger side. In an attempt to up the carats corners are cut and not in a good way. They will be lacking in brilliance and in general will be less appealing.

There is a reason that many retailers do not deal in Fair Cut quality diamonds. They may be inexpensive but they just don’t offer the fire that a Very Good or a Good cut diamond can for that matter.

Final Thoughts

Cut quality is very important for diamond cuts like round brilliant and princess which are designed for maximum brilliance. The cut must be as close to perfect as possible to get the best out of the diamond and with today's technology this is easier to do than you might think.

For the sake of an 02 extra carat in weight some diamond-cutters will sacrifice cut quality to save material. This to a point is fine because it can lead to more affordable diamonds but eventually you lose the whole point of the cut in the first place.

Reference Diamond Size Chart

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