The Ring Concierge 4Cs Diamond Buying Guide

You've likely heard about the 4Cs of diamonds: cut, color, clarity, and carat weight. These four attributes are the most important when determining which diamonds meet your particular preferences and standards, especially when it comes to choosing the diamond for your engagement ring. You'll also want to focus on different attributes depending on the diamond shapes you're most interested in—for example, only round diamonds receive a cut grade. Here, we've put together a guide to the 4Cs to help you in the decision-making process.


The GIA does not regard color as a quality indicator, yet it's still something to understand and be aware of when shopping for the diamond. GIA grades diamonds on their absence of color, on a scale from D to Z. D is completely colorless, and Z being light yellow or brown in color. Colorless diamonds are very rare, resulting in a higher price point. Because it can be extremely difficult to detect the difference between a colorless and a near-colorless diamond, we recommend opting for near colorless diamonds to optimize price and carat size without sacrificing beauty!

When it comes to assessing color, antique diamonds are different from modern diamonds. At Ring Concierge, we work from the colorless range through the faint range for antique diamonds. This is because they face up at least two colors whiter due to their larger facets and are more rare in general so opening up the color range more provides us with the most options to show our clients.

Color Scale

Colorless — D, E and F stones are all within the colorless range. Since colorless stones are more rare, they command a higher price point.

Near Colorless — It's very difficult for the untrained eye to detect differences in color. A near colorless diamond shows no hints of color, but for a much better value than a colorless stone.

A diamond with K color grade will have slight color to it but will often appear white to the eye. Old Cut Round or Old Cut Cushion diamonds appear whiter due to their antique faceting.

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As diamonds are forming, they develop natural birthmarks called inclusions.The GIA grades for clarity under 10x magnification and this grade is based on the number, size, type, color and texture of the inclusions. We recommend a clarity grade of VS1 to SI1 for the best value—these will have few to no visible inclusions to the naked eye, and will have no effect on the beauty or durability of your diamond. Working lower in clarity allows us to focus the budget on color and size—the two more aesthetically noticeable qualities.

Clarity Scale

Internally Flawless — No inclusions, only blemishes, which are on the exterior of the diamond and extremely difficult to see.

Very Very Slightly Included — The inclusions are so tiny and so few they're difficult for a gemologist to see under magnification.

Very Slightly Included — Very minor inclusions that are visible under magnification

Slightly Included — Inclusions are pronounced under magnification, but usually not noticeable to the naked eye.

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Carat is how the jewelry industry measures a diamond's weight. Although related to size, two diamonds shapes with the same carat weight could look very different. For example, a 1.00 carat cushion diamond would look smaller than a 1.00 carat oval, since an oval is an elongated shape. If you want to make your engagement ring look bigger, you can opt for certain diamond shapes that give the look of a bigger spread for their carat weight.

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Cut can refer to the shape of the diamond, or to the quality of the craftsmanship of the diamond. Only round diamonds receive a cut grade, which is determined by how well proportioned the diamond is. The cut grade is a measure of how each part of the stone has been crafted to maximize the diamond's sparkle and brilliance. Since fancy shapes (any diamond besides round) vary in proportion depending on the diamond cutter, they don't receive a cut grade.

So how can you measure the craftsmanship of a fancy shape diamond? All diamonds receive grades for polish and symmetry. A diamond's polish grade is based on the exterior of the diamond—it needs to be perfectly smooth so light will reflect and sparkle. Symmetry refers to the alignment of a diamond’s facets. If the facets are correctly aligned, they'll act like mirrors and bounce back the light so your diamond sparkles and shines.

Cut Scale

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See more frequently asked questions on our engagement ring FAQ page.