One carat equals 0.2 grams, or 200 milligrams, and is the standard unit used to measure a diamond’s weight. Carat weight is a key factor in a diamond’s price, as larger diamonds are rarer and generally more expensive. The carat system also makes it easier to group diamonds of similar weight rather than listing precise measurements in milligrams.

It’s important to remember that a higher carat weight does not always mean a diamond will look larger. Diamonds of the same weight can appear different in size depending on factors like cut, which greatly affects visual appearance. For this reason, a one-carat solitaire often costs more than multiple smaller diamonds totaling the same weight. When comparing diamonds, evaluating price per carat helps provide a more accurate comparison.

Diamond clarity describes the natural blemishes and inclusions found in a diamond. These characteristics form naturally and vary from stone to stone.

Clarity is graded under magnification, ranging from Flawless (F) to Included (I). Diamonds with fewer visible imperfections are more valuable. While flawless diamonds are rare, VS and VVS grades offer excellent beauty and value, and many SI diamonds appear clean to the naked eye.

Diamond color refers to how much natural color is present in a diamond. Colorless diamonds allow more light to pass through, resulting in greater brilliance and sparkle. The whiter the diamond, the higher its value.

Diamond color is graded using the GIA scale, ranging from D colorless to Z light yellow or brown. Grades D to F are the most rare and valuable, while lower grades can still appear colorless to the untrained eye. The setting also matters, as higher color grades pair best with white metals, while slightly lower grades can look beautiful in yellow gold. Fluorescence may be present under ultraviolet light but is typically not visible and comes down to personal preference.

Diamond shape refers to the outward appearance of a diamond, while diamond cut describes how well the stone reflects light. Cut is one of the most important aspects of the 4Cs, as it directly affects a diamond’s brilliance, fire, and sparkle.

A well cut diamond allows light to enter, reflect internally, and return through the top, creating maximum brilliance. Poorly cut diamonds allow light to escape through the sides or bottom, reducing their sparkle. Cut quality is determined by proportions, angles, and finish, especially how depth relates to diameter.

Cut grades range from Ideal and Premium to Very Good, Good, Fair, and Poor. Ideal and Very Good cuts offer the best light performance, while Good cuts provide strong brilliance at a more accessible price. Fair and Poor cuts reflect less light and prioritize carat weight over visual beauty.