The below text is taken from the Gemological Institute of America (GIA) website. We agree whole heartedly with the GIA's guidelines, and urge our clients to make a stone choice based on their recommendations. However, each and every person has different preferences, so please let us know if you have very specific desires.

Each of the 4 C’s (Cut, Color, Clarity and Carat) play a role in a diamond’s beauty, though it is difficult to decipher one component by itself. As a comprehensive whole, the 4 C’s interact with one another within each diamond. As a general rule, we suggest a high quality Cut above all else—as this greatly impacts a diamond’s beauty and brilliance—while balancing a fine line on Color and Clarity to get the best bang for your buck. With the right Cut, both a .9 Carat Round Brilliant (K Color, VS2 Clarity) and a 1.5 Carat Round Brilliant (I Color, SI1 Clarity) can be stunning. It is imperative that you find the right balance of diamond characteristics and value using the 4C’s.  Let’s say you have a budget of $5,000. You have three options: You can go with the absolute best quality possible and then you end up with only a 3/4ct diamond. You can ignore quality and up with a 1.75ct diamond that looks terrible. Or you can find the right balance and end up with a beautiful 1.25ct diamond like this. 

A diamond’s quality is determined by the 4C’s: 

• Cut: Quality of the angles, proportions, facets, and finishing details.
• Color: How colorless the diamond is. 
• Clarity: How clean the diamond is of inclusions and blemishes.
• Carat: The weight of the diamond.

The ‘Cut’ is perhaps the most important aspect of a diamond quality that impacts a diamond’s beauty. Diamond Cut specifically refers to the quality of a diamond’s angles, proportions, symmetrical facets, brilliance, fire, scintillation and finishing details. These factors directly impact a diamond’s ability to sparkle, along with its overall aesthetic appeal. For example take a look at this beautiful diamond and this horrific choice. The only issue differentiating the two is the cut.

The GIA diamond cut chart grades Diamond Cut on the scale of Ideal, Excellent, Very Good, Good, Fair and Poor. The Ideal and Excellent grades, depending on Diamond Shape, signify proportions and angles cut for maximum brilliance and fire.

Even if two diamonds are given the same grade on the diamond cut chart, cuts vary significantly among diamonds and diamond cutters. At times, a cutter may aim for maximum Carat weight, leaving the diamond too deep or too shallow for optimal light reflection. Other times a diamond may be cut to minimize the number of inclusions, improving its Clarity, but forgoing maximum sparkle. Even an Ideal cut diamond may have a yellow tint that is too noticeable and detracts from the gem’s beauty.

More importantly, though, is ensuring Cut is a focal point of your diamond selection. Even a pristine 2 Carat Diamond with no blemishes or color tinting can be dull if it’s not cut exceptionally well. Cut is the biggest indicator of beauty, and should be made priority over the other C’s. As an example, this 1.50 Carat Round Brilliant is graded well for each “C” but lacks a vivacious sparkle.

It’s essential to note that a top grade designation on the diamond cut chart, such as Excellent, doesn’t necessarily indicate an outstanding diamond cut. Almost 55% of all diamonds sold online are Excellent cuts. Some are stunning, while others are mediocre. An example of an exquisite Excellent cut diamond is this 1.5 Carat Round Brilliant from James Allen.

Also, you might have heard about triple ex diamonds (excellent cut, polish and symmetry). A lot of people think that these diamonds are worth the premium some jewelers are charging but the reality is a bit different. You can read more in our Triple Excellent article that explains it in more depth.

Because Cut is so important to a diamond’s fundamental beauty, it’s crucial to review a diamond’s Cut carefully and ask for the eye of an expert.

Diamond Color is graded in terms of how white or colorless a diamond is. The GIA grades diamonds from D to Z, with D being the most colorless, and Z containing noticeable brown or yellow tint. The diamond color chart below shows how each grade looks next to each other.

The pricing of diamonds usually reflects the grade—sometimes significantly. In most cases, the naked eye cannot tell the difference between two adjacent color graded diamonds, though the price difference may be significant.

The most critical aspect with Color is to determine if it appears colorless in relation to its setting. You also want to be certain that a diamond is clear of any tinting that takes away or interferes with white and colored light reflections. The K Color in this Cushion Cut Diamond, for example, distracts from the sparkle of the diamond while this I Color Diamond is radiant.

Brilliance, or sparkle, is created from the way the diamond is cut. It is not advantageous to purchase a diamond that distracts from this important principal characteristic.

As a general recommendation, review each diamond closely and ask for the assistance of an expert. This is the best way to ensure you’re not paying for a feature (i.e. too high of Color grade) that will go unnoticed, or purchasing a diamond that distracts or interferes with light reflection.

Note: Certain colored diamonds are valued stones, like a fancy pink or green diamond. Color grades for these diamonds are distinctly different from traditional “white” diamonds and don’t appear on the diamond color chart.

A Diamond’s Clarity grade evaluates how clean a diamond is from both inclusions and blemishes. Clarity is graded by the GIA on the following diamond clarity chart:

• FL (Flawless)
• IF (Internally Flawless)
• VVS1 (Very, Very Slightly Included 1)
• VVS2 (Very, Very Slightly Included 2)
• VS1 (Very Slightly Included 1)
• VS2 (Very Slightly Included 2)
• SI1 (Slightly Included 1)
• SI2 (Slightly Included 2)
• I1 (Inclusions 1)
• I2 (Inclusions 2)

This diamond clarity grading scale shows and sums up each clarity grade. Watch how the visibility of the inclusions changes in the image on the right.

Internally Flawless / Flawless – No internal or external imperfections. Flawless diamonds are extremely rare.

Depending on the size, location and darkness of blemishes and inclusions, these imperfections can interfere with light as it passes through the diamond. When this happens, the brilliance and beauty of the diamond is dulled, taking away from the high quality Cut.

For Clarity, our primary recommendation is to ensure the diamond is eye clean, and that inclusions are not interfering with light reflection.

Review the stone to see if it is eye clean and ask for confirmation from an expert. A certificate alone won’t tell you how a diamond’s blemishes will impact the stone’s appearance and brilliance.

In our opinion, a consumer’s goal should be to find the cheapest (in regards to clarity; other factors matter as well) “eye-clean” diamond you can find. We use “eye-clean” to describe diamonds that may have inclusions if you look at them with a magnifying glass (or microscope or loupe), but the typical person can’t see the inclusion with their naked eye.

We have recently developed Ringo, a patented artificial intelligence model, that can examine videos of diamonds and determine if they are eye-clean. Ringo will also filter for other parameters like making sure the diamond is well-cut, doesn’t have fluorescence issues and will match the style setting you choose.

iv. Carat Weight

Often when people hear the term “Carat Weight,” they think it refers to the size of the diamond. In actuality, Carat refers to the weight of the diamond, not how large the stone is. A 1 Carat Diamond equals 200 milligrams, or 0.2 grams—and weighs about the same as a quarter of a raisin. Depending on the Diamond’s Shape and how it is cut, two 1 Carat Diamonds might be quite different in size.

 

While Carat weight is an element to consider when buying a diamond, the overall appearance and brilliance should carry more importance. For example, a mediocre 1.5 Carat diamond will not shine as brightly—or draw as much attention—as a stunning 1.0 Carat diamond, no matter how much more it weighs. Rather than sticking to a certain number on the diamond carat weight chart, choose a diamond with an Excellent cut or Ideal cut in the shape you desire.

______________________________________________________

HOW THE 4 C’S WORK TOGETHER

Each of the 4 C’s contribute to the overall beauty of a diamond and make each stone unique. A Diamond, however, should be viewed as an organic whole. Because the eye has difficulty differentiating one diamond characteristic by itself, such as Clarity or Color, it is important to consider how the 4 C’s impact each other.

Which is the most important of the four C’s?

• Cut: The most important of all the diamond characteristics as it most readily impacts a diamond’s beauty. Look for high levels of brilliance and fire, and be willing to reduce your spending in other areas like Clarity or Color to ensure an exceptional Cut.
• Color: The second most important aspect to focus on. A diamond should look white or colorless to the naked eye. Ensure the Color does not distract or interfere with white and colored light reflection.
• Clarity: The third most important characteristic on the list. Choose a diamond that is eye clean. Blemishes and inclusions should not distract from the brilliance or fire of a diamond.
• Carat: Last but not least. Consider what is important for you and the one you love, but remember that brilliance and beauty will outshine mere weight each and every time. Be open to lowering your Carat weight to ensure you purchase a stunning diamond.

With these fundamentals in mind, remember that a diamond is a precious whole, and should be looked at in totality. The four main qualities of a diamond all play an important role in how the diamond looks.

 

Learn More by Visiting GIA's website