Learn how to evaluate a diamond based on four key characteristics. As you explore engagement rings, you’ve probably heard the phrase “the four Cs.” This phrase refers to the four qualities used to describe a diamond—cut, color, clarity and carat.
People often assume a diamond’s cut is synonymous with its shape, but that’s actually incorrect. The cut of a diamond refers to how well the stone was faceted, proportioned and polished, and it’s the only quality not influenced by nature. Only precise craftsmanship and artistry can affect a diamond’s cut. It’s the most important of the 4Cs because it determines how a diamond interacts with light—meaning how much it ultimately sparkles. For this reason, the cut has the greatest influence on the appearance of a diamond.
When determining the grade of a diamond’s cut, experts evaluate three light-reflecting qualities. The first three are:
Internal and external white light reflected from a diamond.
The scattering of white light into a rainbow’s spectrum of colors.
The flashes of light, or sparkle, a diamond produces.
In total, a diamond’s brightness, fire and scintillation are often referred to as a diamond’s “brilliance,” the diamond’s overall ability to return light to your eye.
Diamond cuts are graded as Excellent, Very Good, Good, Fair, and Poor. We suggest purchasing a diamond that’s graded either Excellent or Very Good for your engagement ring. A well-cut diamond will be stunning and bright almost regardless of color or clarity, whereas a colorless, perfectly clear diamond will appear dull and lifeless if it’s cut poorly.
The second most important quality to look at when considering a diamond is its color rating. The highest quality diamonds actually have an absence of color, whereas lower quality diamonds have a pale yellow hue to them.
Diamonds are graded on a scale D-Z, and each letter grade represents a range of color
Colorless or near colorless diamonds are recommended for engagement rings, as the less color a diamond has, the brighter the light passing through it will appear.
However, it’s important to keep the diamond’s shape in mind as well when considering it color grade. A round brilliant diamond can hide color imperfections more easily than an elongated shape, like an oval, pear or radiant. For these shapes, a higher color grade might be necessary to avoid a noticeable tinge.
The third C refers to the natural imperfections within a diamond or on its surface. Most of
these inclusions or blemishes are impossible to see with the naked eye, though diamonds with the least amount of these imperfections are rated the highest on the clarity grading scale.
Diamonds are graded from FL (flawless) to I (included), and although we recommend choosing a highly rated diamond, it’s most important that the diamond appears “eye clean” — regardless of its actual rating.
This is where the balance of the 4Cs comes in. You can choose a diamond that’s higher on the color scale but lower on the clarity scale (as long as there are no eye-visible inclusions) to save money without sacrificing quality or beauty.
Clarity is also more important for some diamond shapes than others. For instance, asscher or emerald-shaped diamonds require a higher grade of clarity to look most their very best due to their glassy, smooth tops.
The last of the 4Cs is carat, which is used to describe the actual weight of a diamond.
One carat is equal to 200 milligrams. The more carats the diamond has, the most expensive it is.However, a diamond’s carat doesn’t actually refer to its size, as it’s commonly mistaken. In fact, two diamonds that have the same exact amount of carats can look radically different in size due to their other Cs—cut, color and clarity—as well as their shapes. Elongated shapes, such as ovals, pears or marquise, can appear larger than their carat weight.