Diamond Quality: Carat, Color, Clarity and Cut

The biggest diamond isn't always the most valuable. The price of a diamond is determined by the four C's: color, clarity, carat, and cut. If you know what to look for, you could find a diamond that looks almost identical to that gorgeous, expensive one your fiancee's been eyeing–at a fraction of the price. Below is a summary of the four C's.

Color. This refers to the tint of the diamond. A perfectly clear, colorless diamond is very rarely found in nature–and its rarity gives it great value. Around 98% of diamonds on the market today have some yellow or brownish tint. In some, it's barely discernible. In others, it can affect the brilliance of the diamond. Diamond color is rated on a scale from D–which indicates a completely colorless diamond–to Z, which describes a diamond with a visible yellowish tint.

Some diamonds have colors much richer than the Z rating describes. Once they go beyond the rating system, the value of the diamond starts to go up again. Some rare diamonds come in blues, reds, pinks, greens, and even canary yellows. These can be just as valuable as colorless diamonds, and sometimes more so. Read on for more information about Diamond Color.

Clarity. This quality refers to the flaws, both internal and external, found in the diamond. A completely flawless diamond is extremely rare and valuable. Most will have at least a few internal flaws–called inclusions–that can be caused by contamination from other minerals when the diamond was formed, as well as cracks and inconsistencies within the diamond's carbon matrix. External flaws, called blemishes, appear on the surface and are often caused during the cutting and polishing process.

When judging a diamond's clarity, an appraiser examines the stone under 10x magnification. Through most of the rating scale, the flaws found in a diamond are not visible to the naked eye–one reason you may find two identical-looking stones at a jeweler's, one a great deal more expensive than the other. The more expensive diamond is probably flawless or nearly so, while the other has flaws visible only under magnification.

Learn more about Diamond Clarity.

Carat. This refers to the weight of the diamond in milligrams. A single carat is one-fifth of a gram, or 200 milligrams. Jewelers often describe their diamonds using a point system determined by the carat size. The point system provides a convenient–and more impressive–way of describing diamonds that are less than one carat. For example, a half-carat diamond is .50 of a carat, and a jeweler will call it a "50-point" diamond.

Certain carat values can cause big price jumps. For example, a 96-point diamond may look almost identical in size to a 100-point diamond–but one is not quite one carat, and the other is. If both diamonds have similar cut, clarity, and color ratings, expect the 1-carat diamond to be priced much higher. Its size is more popular than a diamond under the 1-carat mark, so people are willing to pay more.

We provide additional in-depth information about Diamond Carat.

Cut. This refers to the way the diamond has been shaped. Diamonds must be cut under very precise proportions and angles for maximum brilliance, and a bad cut can greatly diminish a gem's value. Many jewelers will tell you that a diamond's cut is the most important factor in determining value. Because the cut so strongly affects the brilliance and fire of a diamond, it's the one quality you shouldn't compromise on. Read more about Diamond Cut.

While cut refers to how well the shape matches the ideal proportions for the style, the same word is also used to refer to the shape of the stone as well. For example, round brilliant, princess, emerald and heart shaped can be referred to as different cuts. We provide more information on Diamond Shapes. However, as discussed above, cut as a quality measure refers to a grading system on how ideal the particular shape was cut to maximize brilliance, fire and beauty.

The combination of each of these qualities is unique in each diamond. Most of us can't afford a diamond with sky-high ratings in each of the four C's. But with a little skillful balancing of these qualities, you may be able to find a diamond that's just as beautiful–and much less expensive.

Discover more about Diamonds: History, Diamond Jewelry, Engagement Rings, Quality, Carat, Color, Clarity, Cut and Shape.