Many of our readers will be considering a major diamond purchase this season, so we thought this would be a great time to present our mini refresher course on the "4C's of Diamonds."
Cut. This is what gives a diamond its fiery sparkle. Each diamond, regardless of shape, is cut according to an exact mathematical formula. For example, a round, brilliant-cut diamond has 58 "facets," or small, flat, polished planes that are designed to yield the maximum amount of light. This reflection, known as brilliance, is an extremely important factor in evaluating the quality of a diamond.
Color. Diamonds can be found in every color of the spectrum, but in "white" diamonds, the most valued gemstones are those with the least color. White diamonds are graded on a scale beginning with "D," indicating a total colorlessness, progressing down the alphabet for lower qualities. The best way to see the true color of a diamond is by looking at it against a white surface.
Clarity. A diamond's clarity is determined by any external irregularities and the number of internal "inclusions." Most diamonds contain some inclusions, but many are microscopic in nature and can be seen only under powerful magnification. Spots, bubbles or lines are marks that make each stone unique, but generally, the fewer the inclusions, the more valuable the stone. Clarity is graded on a scale ranging from "flawless" to "imperfect."
Carat. Referring to a diamond's weight, this word is derived from the carob seeds that were used to balance scales in ancient times. For jewelry purposes, carats are further divided into points, a one-carat stone equaling 100 points. Therefore, a half-carat stone may be referred to as "50 points," a quarter-carat, "25 points,"etc.
Graduate Gemologist, GIA
Certified Appraiser