It’s easy to think that size is the most important factor in picking out a diamond. But that’s not necessarily the case. Sure, size (or carat weight, if you want to get technical about it) is a big deal, but there are a few elements to consider when it comes to finding the perfect rock.

Jewelers have a simple way for gem-savvy consumers to remember the important bits: “The Four Cs,” as it were, represent the four most important qualities to consider. We’ve already gone over carat weight; the other three are cut, color, clarity. Let’s go over each one individually.

Carat Weight

We covered this briefly. Diamonds aren’t sold by size, per se, but rather by weight, and carats are the unit stones are measured in. Since stones come in different shapes, this is the easiest way of determining overall size. For quick reference, one carat is equal to about 0.2 grams; five carats is equal to a stone that weighs 1 gram, and so on.

Cut

The luster and brilliance of a diamond is actually more dependent on cut than any other factor. A diamond that’s cut imperfectly allows light to bleed through at awkward angles; a diamond that’s cut perfectly, meanwhile, reflects light from all possible directions, and out through the top of the stone. This gives a diamond its sparkle. Keep in mind, “cut” isn’t the same as “shape:” shape is round, oval, pear, etc; cut refers to a diamond’s proportions, and the angle of the facets.

Color

Diamonds come in a variety of hues – pinks, blues, yellows – and these colors are due to the trace presence of other elements mixed in with the carbon. Different shades are prized differently, but a whiter, clearer stone reflects more light, and generally increases the value of the finished product. The GIA rates diamonds on an alphabetical scale, from D (colorless) to Z (heavily tinted). While a diamond of, say, an H grade might be slightly tinted (and only discernable from the “pavilion,” or the bottom), it’s discernibly the identical to a diamond rated D, if its setting and surroundings are taken into account—for example, if set into a lighter metal like white gold or platinum.

Clarity

All diamonds are not created equal. Rather, they’re forged deep within the earth, under extreme heat and pressure. As a result, each stone contains “fingerprint” called inclusions that determined the extent to which the light passes through a stone (also called “brilliance”). The GIA qualifies stones on a scale from “flawless” (very rare, but discernibly perfect, even under close inspection, even by a microscope or a jeweler’s loupe), to “included” (containing inclusions that are visible to the naked eye).

Conflict

At Pinner & Co. (as is the case with a number of responsible brands), we incorporate a fifth “C” that might be more important than any of the other four: conflict. We go out of our way to ensure that all of our gems are certified conflict free, and have never been harvested from the earth via slavery or underpaid labor. History has shown that, for something so beautiful, a diamond can have a terrible past; it’s up to manufacturers and consumers to demand only the best — as far as the quality of the stone itself, as well as its story.