Selecting a Diamond

So you are ready to make your dream ring, but how do you choose the right diamond?

There’s a lot to unpack when it comes to diamonds, and many more factors to consider than just the carat size, origin, and cut shape. Because of this, many people choose to have their diamonds graded by a reputable source such as the Gemological Institute of America to guarantee high quality. Here is a basic guide to the values they grade diamonds on, as well as useful bits of advice from our experts to help you make an informed decision. 

What are the four C’s? 

Before we get into shopping for diamonds, let's review the essential characteristics that are used internationally to grade diamonds. The four C’s have been used to evaluate diamonds since the GIA standardized them in the 1940s. Today, they are used only to grade natural diamonds, not lab-created ones. Let’s explore what they are, and then see how lab diamonds are graded differently. 

Cut Grade

A diamond's cut grade refers to the stonecutter's precision and a geometry that allows the stone's facets to interact with and reflect light. A well-cut stone has the sparkle, fire, and brilliance we all associate with diamonds.

Color Grade

A diamond's color grade refers to the absence of color. The highest-rated diamonds are colorless or near-colorless. This is because a perfectly formed diamond free of impurities is colorless, like a drop of water.

Clarity Grade

Diamonds are formed deep under the earth under tremendous pressure; impurities imparted during the growth process can form "birthmarks" Called inclusions or blemishes. A diamond's clarity grading refers to the lack of impurities, the highest rating being FL (flawless), which means a skilled grader can find no impurities at 10x magnification.

Carat Weight

Diamonds and other gemstones are weighed in metric carats. This is different from gold karat, which refers to gold purity. One carat equals 0.02 grams and is divided into 100 points; for example, a fifty-point diamond is equivalent to 0.50 carats.

Grading Lab Diamonds

As of 2025, the GIA no longer grades lab diamonds based on the 4 C’s. Instead, they confirm whether the diamond has been lab-created, and then sort it into one of two categories: premium or standard. Diamonds that fail to meet the standard requirements do not receive a grade at all. 

The reasons for this shift from the 4C’s grading system is because 95% of lab diamonds are of a more consistent quality than natural, tending to fall into the same range of color and clarity as each other. It is rare that a lab diamond doesn’t have a good color grade, for example. Using the same grading system as natural diamonds can also mislead customers into thinking they are the exact same product, and the GIA does not want them to be mistaken as the same thing. 

Advice from Our Experts

Libby Master Goldsmith & Expert Stone Setter "One misconception is that diamonds are indestructible. Diamonds are the hardest substance on earth. However, they are not the most durable. It's important to know that diamonds can break if force is applied at the right angle. The diamond’s cut and the design of its setting can either increase or reduce the likelihood of a diamond cleaving or fracturing. Shapes with thin, sharp edges are more likely to fracture than round stones. Just as well, settings that leave much of the diamond exposed, like a four-prong setting, leave the diamond more susceptible to fracture than a bezel, which protects all the edges of the stone. The shape of the stone you choose and the setting should all be considered in terms of durability and wear over time."

Stacey Owner, Jewelry Designer, and Goldsmith "Clients are often surprised to hear that their heirloom diamond has chips or cleaves. Though it doesn't always happen, as Libby mentioned, diamonds are not the most durable substance on earth, and it is possible. When I meet with a new client, I try to work with them to create a piece that fits their aesthetic and will offer the best possible protection for the stones. One option to consider when working with an existing diamond is recutting. This allows us to take a diamond that may not have the appeal we expect and come away with something precision cut for fire and brilliance. It's important to remember that you will lose carat weight when recutting, but it may be well worth it for a diamond that is cut poorly or in bad shape from years of wear."