The Diamond Standard: How to Choose the Perfect Stone

You’ve probably heard of them: The four Cs are the benchmark for deciding on your perfect diamond. Here, Allison Neumann, the maven behind her eponymous jewelry shop, parses each one in simple terms for those looking to put a ring on it.

Cut

A diamond’s cut is often confused with its shape. The latter refers to its outline—round, oval, pear, emerald, etc.—but the former refers to its facets. The cut is actually the most crucial of the four Cs, because it breathes life into the diamond and directly impacts its sparkle. It’s also the most complex and difficult to assess. A well-cut diamond will let more light return through the crown, or top, of the stone—and a well-cut and well-polished stone will ignite its fire—while a shallow-cut diamond will allow light to escape from the side of the stone or leak out the bottom. Having a well-cut diamond is essential to having a sparkle that can be seen from across the room.

Clarity

Clarity is an evaluation of the number, size, and placement of internal inclusions and external blemishes. The fewer inclusions and blemishes the diamond has, the closer to flawless it is and the better its clarity grade. Most couples choose an engagement diamond that is somewhere in between, because imperfections aren’t typically recognizable without a jeweler’s loupe or microscope. However, a diamond’s unique imperfections can be a great identifier. Like snowflakes, no two diamonds are exactly alike, so getting to know your inclusions helps you recognize your diamond.

Color

Many people think of diamonds as colorless, but most actually have a small amount of color, usually yellow or brown. In this case, the term actually refers to the absence of color. The difference in color grades can be difficult to detect for the untrained eye, but color directly impacts the overall quality and price of the stone. The less color in a diamond, the more desirable and valuable it is. Many brides prefer engagement diamonds that are “colorless” (labeled D–F on the Gemological Institute of America’s scale) or “near colorless” (G–J), but they can range to “faint” (K–M), “very light” (N–R), and “light” (S–Z).

Carat

Carat is the metric measurement of a diamond’s physical weight, equal to one-fifth of a gram and subdivided into 100 points—this allows precise measurements to the hundredths decimal point (.01). But sometimes engagement rings are described in terms of total carat weight, and understanding diamond terminology is essential if you’re going to make a smart purchase. Diamond price increases with carat weight, but two diamonds of equal carat weight can have very different costs if the other Cs differ between them.