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Let’s Not Cut Corners : Is Diamond Cut the Most Important 4C?

Nobody wants a big dull rock on their finger. And we’ll say it for the folks in the back. When you’re buying a diamond, you might think about size and how much it matters. Or, you may focus on whether or not it’s flawless (hello, Beyoncé). Maybe you even consider purchasing a pink or green or yellow one (if you’re J.Lo). But at the end of the day, what you’re really after is sparkle. It’s that undeniable brilliance that catches your eye from across the room not the specific weight, color, or clarity of the stone. And this, my darlings, is why diamond cut is also undeniably the most important of the 4Cs. Here’s our argument:

What Is Diamond Cut?

So, we’ll start at the beginning. Cut is one of the 4Cs of diamond grading. They are as follows: Cut, Color, Clarity, and Carat Weight. And diamond grading is what determines the price of all diamonds on the market today. So it’s kind of a big deal. Cut also describes the shape of a diamond, as in “round brilliant cut” or “cushion cut”. But that’s not what we’re talking about here.

In this context, “cut” refers to the actual proportions, symmetry, and polish of a diamond, rather than its shape. A well-cut diamond will allow light to enter the stone, reflect internally, and disperse back out through the crown. The result is an exceptional brilliance and fire your pretty little eyeballs enjoy. So which diamond cut sparkles the most? Well, the one with the best proportions, polish, and symmetry of course!

A round brilliant diamond cut  set in a two tone bezel ring
No, when we talk about diamond cut we’re not talking about diamond shape. The two, though used interchangeably, are very different.

How is Diamond Cut Grade Determined?

The cut grade of diamonds is assessed from “Excellent” to “Poor” by gemological laboratories like Gemological Institute of America. Cut grade takes into account factors such as brightness, fire, scintillation, and overall visual appeal. It takes a whole lot of training to tell the tiny differences in all those little facets. Luckily today we also have great technology to help us out.

What the experts are looking for:


The proportions of a diamond refer to the angles and dimensions of its facets relative to one another. A well-cut diamond will have proportions that allow light to enter the stone, reflect internally, and disperse through the crown. This allows that diamond to dazzle in a dashing display of brilliance and fire.

An almost flat appearing Asscher cut diamond
Proportions vary by diamond shape so it’s important to do your research before committing to any diamond. Typical proportions include: Depth %, Table %, Culet, Girdle, and the Length/Width ratio.
A three stone engagement ring has three Marquise cut diamonds. Below the ring is a diamond pave chevron band.
Get an even more symmetrical style with a seriously sparkly three stone engagement ring.


Symmetry refers to the precision and alignment of the diamond’s facets, including the facets’ shape, size, and placement. A diamond with excellent symmetry will have evenly balanced facets that create a symmetrical pattern when viewed from different angles.


Polish refers to the smoothness and quality of the diamond’s surface finish. A diamond with excellent polish will have smooth, polished facets that allow light to pass through without obstruction, maximizing its brilliance and sparkle.

A radiant cut diamond with claw prongs
Think smooth and go for diamonds with high rated polish for that iconic glimmer and glamor. Want to see your diamond’s polish grade? Just click ‘View Certificate’ to see additional grading criteria.
A compass prong oval diamond engagement ring with prominent bow-tie
One very important thing to keep in mind when purchasing a diamond that has an elongated shape is the bow-tie.

What You Should Be Looking For With Diamond Cut

An ‘excellent’ or ‘ideal’ cut grade signifes a diamond’s optimal light performance. It balances brilliance (white light reflection), fire (color dispersion), and scintillation (sparkle). In contrast, a poorly cut diamond may appear dull, lifeless, or lackluster due to light leakage, poor symmetry, or improper proportions. Hence, that big dull rock on your finger. No fun.

One super important thing to know, however, is that currently only round diamonds have official, industry standardized cut grades. This is because round diamonds are the most studied and popular diamond shape. If you are searching for fancy shapes (which is any shape other than round), you won’t see an official cut grade listed on a diamond grading report or certificate. You will, however, see proportions, symmetry, and polish.

The Debate Surrounding Diamond Cut vs. the Other 4Cs

All those things considered, let’s talk about why exactly diamond cut (besides being visually appealing and, well, sparkly) is so much more important than the other 3 of the 4Cs. What it comes down to is that a diamond’s sparkle (it’s cut) is the most visually impactful of the 4Cs. It’s what your eye picks up on first, and it has a lot of impact on the other 4Cs as well.

For instance, a well cut diamond can help disguise inclusions (which means you might be able to go for a lower clarity grade), help make a diamond appear brighter (you might be able to go for a lower color grade), and even make a diamond look larger than its carat weight because the diamond’s weight is so well distributed and the light return more even and bright.

Prioritizing diamond cut can save you big down the line as an ideal cut diamond can help a diamond appear both brighter and less included.

Evaluating the Importance of Other 4Cs

So, what exactly do you need to know about color, clarity, and carat weight? These other three main factors are part of the big equation that evaluates the quality and value of a diamond. Here’s a quick rundown of each:


It’s the second most noticeable (to the untrained eye) of the 4Cs. Color refers to the presence or absence of color in a diamond, with the most valuable diamonds being colorless or exhibiting minimal color. The Gemological Institute of America (GIA) grades diamond color on a scale from D (colorless) to Z (light yellow or brown).

Different diamond shapes display their body color differently, and you’ll often see more color in deeper cuts, or concentrated at the points of fancy shaped diamonds. Colored diamonds, such as fancy yellow or pink diamonds, are graded on a separate scale and valued based on the intensity and rarity of their color.

A side profile of a cushion cut champagne diamond ring with claw prongs
While D-graded diamonds are undeniably stunning, the light yellow hue of champagne diamonds or smoky brown of cognac diamonds can be just as special.
A highly included, champagne, trillion cut diamond
Bad clarity isn’t all that bad. Salt and pepper rings are highly included gems that are prized for their unique and interesting stone patterns.


While many folks get hung up on diamond clarity, it’s actually the least noticeable to the naked eye. For instance, you’ll never see a visual difference between a flawless diamond and a VVS clarity stone.

The GIA grades diamond clarity on a scale from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions and blemishes visible to the naked eye). Clarity grading takes into account the size, type, position, and quantity of inclusions and blemishes within the diamond to determine its grade.

Carat weight

It’s important to remember that carat weight is a measure of a diamond’s physical weight and not its visual size. One carat is equal to 0.2 grams. But again, this weight can be distributed quite differently from one diamond to the next depending upon its overall shape, cut, and proportions. There’s really no answer to “which diamond cut is the biggest” because there are just too many other factors at play.

A seven carat oval cut diamond engagement ring
Think a 7-carat diamond is too big for your budget? Think again! Lab grown diamonds are more affordable than naturally mined diamonds while maintaining the same physical and chemical identity.
A center oval cut diamond is framed by two accent oval stones.
There is true beauty in balance. Find your perfect balance by exploring our collection now.

Finding Balance: The Interplay of the 4Cs

Ok, so now you’re a know-it-all about diamonds and the 4Cs, but what are you going to do with it? Buy a diamond, of course! Kidding, sort of. But let’s see how these all work together and how you might determine which diamond cut is the most expensive of the bunch.

When purchasing a diamond, it’s essential to consider how all of the 4Cs work together. Big picture, though, they can act like levers you can push or pull to find a diamond that’s the perfect balance of your budget and preferences. Some folks might prefer a larger diamond but are okay sacrificing color, while others might want a higher clarity grade but are ok with a smaller stone.

You have to do you, after all. But in any equation, just remember not to sacrifice on the cut grade of the diamond because you can get a high color, high clarity, high carat stone with a poor cut grade and trust, you won’t like it.

The Diamond Experts Agree

Really, though, ask any of them. Diamond cut is by far the most important of the 4Cs because it really has so much impact on a diamond’s beauty and brilliance. While color, clarity, and carat weight are factors to consider (and play a part in diamond pricing), they just won’t be that noticeable to the naked eye. But a diamond’s sparkle? That can’t be beat. 

Explore our collection of more than 10,000 natural and lab grown diamonds on your own or reach out to our diamond experts at with a bit about what your dream diamond looks like and, obvi, your budget, and we’ll get you sorted. Want to go straight to customizing an engagement ring? Try our design quiz to work out all the details and get a free sketch!

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