Cut | Color | Clarity | Carat Weight | Certification | Care

Before you start diamond shopping, you want to have an understanding of what you're buying. This guide simplifies the four Cs of diamonds — cut, color, clarity, and carat weight, so you can select your diamond based on the same criteria jewelers use to grade them. After reading through this guide, you'll be ready to choose the diamond that's right for you.

The cut of a diamond has the most effect on its sparkle, or brilliance. Even if the diamond has perfect color and clarity, a poor cut can make a diamond look dull. Blue Nile carries only the highest grades of diamond cut, for the most sparkle. Learn how to choose the right diamond cut with the most brilliance for your budget.

Diamonds with few flaws, or inclusions, are very rare and highly valued. Clarity is graded based on the number, location, size, and type of the inclusions found in a diamond. Blue Nile has some of the clearest diamonds available. Learn how to choose the right grade of clarity for your diamond.

Diamonds with very little color are the most highly valued and are priced accordingly. A little color can diminish a diamond's brilliance. To help you choose the most brilliant diamond, Blue Nile offers diamonds with the highest grades of color. Learn how to choose a diamond with no color noticeable to the unaided eye.
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The weight of a diamond is measured in carats. Since larger diamonds are more rare than smaller diamonds, diamond value tends to rise exponentially with carat weight. Read more about carat weight and learn how to balance diamond quality with the size of your diamond.

The most important step in choosing a diamond is reviewing the diamond certificate, referred to by diamond grading labs as a grading report. A grading report documents the characteristics of a diamond, like the four Cs. Before purchasing a diamond, review a copy of its grading report, as this is your guarantee of quality for that diamond. Learn more about the diamond grading report.