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The 4 C’s of Diamond Grading

June 15th, 2024

six diamonds, some clear, some blue, on a white surface

Understanding a diamond’s value hinges significantly on the 4 C’s, a globally accepted grading method introduced by the Gemological Institute of America in the mid-20th century. This system revolutionized how diamonds are evaluated and compared to each other, providing a consistent framework that has become essential for both consumers and professionals in the jewelry industry. Embracing this method ensures that every diamond's unique characteristics are appreciated and accurately valued. Our team here at Davidson & Licht has compiled a comprehensive guide to help you navigate and understand these crucial grading criteria, enhancing your confidence when selecting diamonds for your next adornment.

a number of small diamonds spilling out of a metal box


The first of the 4 C’s stands for “cut.” The cut of a diamond not only refers to its shape, but also to how effectively it has been shaped and faceted to maximize its innate brilliance, fire, and overall aesthetic appeal. A masterfully cut diamond will beautifully reflect light, making it appear luminous and lively. Grading a diamond's cut involves assessing its proportions, symmetry, and polish, factors that collectively influence its ability to intensely sparkle. This grading is critical because even a diamond with perfect color and clarity can appear dull if poorly cut. The precision of the cut determines the stone’s interaction with light, which is paramount in showcasing its splendor.

an emerald cut diamond on a piece of dark gray fabric


A diamond's evaluation also heavily relies on its clarity, which assesses the presence of internal features, known as inclusions, and external characteristics, called blemishes. Clarity is measured using a scale that ranges from flawless— indicating no visible inclusions or blemishes under 10x magnification— to included, where these features are significantly apparent. The rarer and more valuable the diamond is perceived to be, the fewer inclusions and blemishes are present. This grading scale is rigorously applied by expert gemologists who inspect each diamond under high magnification, ensuring the accurate assessment of each gem’s pristine nature.

six round cut diamonds in a line on a black, reflective surface


Grading a diamond's color involves evaluating how close the gemstone is to being colorless. The scale used ranges from D, which signifies a completely colorless diamond, to Z, which indicates a diamond with noticeable yellow or brown tinting. The closer a diamond is to colorless, the rarer and more valuable it becomes. This grading is meticulously performed under controlled lighting conditions and compared against a set of master stones for accuracy. The subtle variations in tone can significantly affect a diamond's overall appearance and brilliance, making color an essential factor in determining its quality and appeal.

a very close up image of a round cut diamond lying among glass shards

Carat Weight

The value of a diamond is greatly influenced by its carat weight, which quantifies the gemstone's mass. One carat is precisely defined as 200 milligrams. Larger diamonds are rarer and often have a disproportionately higher value as their size increases. This means that a single two-carat diamond typically costs more than twice as much as a one-carat diamond of similar quality. Carat weight is measured with extreme precision on calibrated scales to ensure accurate valuation. While size contributes significantly to a diamond's appeal and price, it is the combination with the other C's— cut, color, and clarity— that truly defines its overall worth and beauty.

a person looking at diamonds through a magnifying glass

Find Incredible Diamonds at Davidson & Licht

Explore exceptional diamond jewelry of the highest quality at Davidson & Licht. Our pristine Walnut Creek, California jewelry store boasts an exquisite selection of loose diamonds and designer engagement rings that cater to every taste and occasion. Additionally, we offer custom design services, allowing you to create a piece that is uniquely yours. With a commitment to excellence and craftsmanship, Davidson & Licht is your destination for luxurious jewelry. For a truly personalized experience, request an appointment with one of our knowledgeable team members, and let us help you find or craft your perfect jewel.