Diamond Guide

Every diamond is graded on the same four qualities — cut, color, clarity, and carat weight, known as the 4Cs. You don't need to memorize the charts. What matters is what each one actually changes when you look at a stone on a hand, so you can decide where your own priorities sit. Here's each C in plain terms.

Cut — where the sparkle comes from

Cut is the one C shaped entirely by human hands. It describes how well a diamond's facets are proportioned, angled, and polished, and it's what decides how the stone handles light. A well-cut diamond throws back bright white light and flashes of rainbow color; a poorly cut one can look flat or glassy even when its other grades are high. Cut is graded from Excellent down through Very Good and Good to Fair. In everyday terms: if you pay attention to one C, make it this one — a slightly smaller stone with an excellent cut will out-sparkle a larger one without it.

Color — how white the stone looks

Diamond color is graded on a scale from D to Z. D, E, and F are colorless. G through J are near-colorless — the range most engagement rings fall in, because any tint is very hard to see once the stone is set and viewed face-up. Further down the scale, a warm or yellowish tint becomes visible. The metal you choose changes the look too: white gold keeps a stone looking crisp and white, while yellow or rose gold warms the whole ring up — and can make a slightly warmer stone look perfectly at home.

Clarity — nature's fingerprints

Almost every diamond carries tiny natural marks called inclusions, formed as the crystal grew. Clarity grades how visible those marks are, from Flawless down through VVS, VS, and SI to Included. In plain terms: VS stones have inclusions that are small and hard to find even under magnification, and SI stones have inclusions that can be found under magnification but usually can't be seen with the naked eye. What matters on a hand is whether a stone is "eye-clean" — no inclusions visible to the naked eye at a normal distance. Many VS and SI diamonds are eye-clean, which is why clarity is often the C where shoppers comfortably trade a grade for size.

Carat — weight, not size

A carat is a unit of weight — one carat equals 0.20 grams — not a measurement of how big a diamond looks. Two stones of the same carat weight can look quite different in size. Shape plays a part: elongated shapes like oval, pear, and marquise spread their weight across a longer outline and tend to look larger for their weight, while a stone cut too deep hides its weight underneath, where nobody sees it. That's why cut and carat belong together: a well-cut stone shows every bit of the size you've paid for.

Shapes at a glance

Round — the classic. Cut for maximum brilliance, and the most popular shape for engagement rings.

Oval — an elongated round. Bright sparkle, and it looks large for its weight.

Princess — square with sharp corners and strong, crisp sparkle.

Emerald — rectangular with step-cut facets. Instead of sparkle, it gives calm, elegant flashes of light.

Pear — a teardrop, rounded at one end and pointed at the other. Distinctive and flattering on the hand.

Cushion — square or rectangular with rounded corners and a soft, romantic glow.

Marquise — long and slender with pointed ends. Of all the shapes, it looks the largest for its weight.

Radiant — square or rectangular with brilliant-style facets, combining a clean outline with lively sparkle.

Asscher — a square step cut with a vintage feel and deep, window-like flashes.

Heart — the romantic one. Quality shows in a balanced, even outline.

Baguette — long, slim, and step-cut. Most often used as side stones alongside a center diamond.

Natural and lab-grown diamonds

Both are real diamonds. A natural diamond and a lab-grown diamond have the same chemical composition — carbon in the same crystal structure — and the same hardness and sparkle. The difference is origin. Natural diamonds formed deep in the earth over billions of years and were brought to the surface and mined. Lab-grown diamonds are created in a laboratory, where the conditions that form diamond are reproduced. The other difference shoppers care about is price: lab-grown diamonds typically cost less than natural diamonds of the same size and quality, which is why many shoppers choose one to get a larger stone. We carry both, and we're glad to set examples side by side so you can compare them with your own eyes.

For a fuller comparison, see our Lab-Grown vs. Natural Diamonds guide.

Both kinds are graded by independent gemological laboratories on the same 4Cs. Ask us about the grading report for any stone you're considering — we're happy to walk through what it says, line by line.

See diamonds in person

Grades tell part of the story; your eyes tell the rest. Visit us at Roxy's Jewelry, Boynton Beach Mall, 801 N Congress Ave, Boynton Beach, FL 33426, or call the store at (561) 739-3339, and we'll put a few stones side by side so you can see the differences yourself. When you're ready to think about settings and styles, read our Engagement Ring Guide, or browse the rings in our bridal collection.