The Four Cs of Diamonds | Color . Clarity . Cut . Carat

Every diamond tells a different story. No two diamonds will catch the light with exactly the same sparkle or reflect the world with the same clarity, which can make choosing a diamond seem far more a mystifying art than an exact science. Fortunately, the qualities that all diamonds share helped gemologists develop comparison and evaluation tools that diamond buyers can also learn to use.

Choosing a diamond that will make a lasting impression begins with the GIA 4Cs of diamond quality. Color, clarity, cut, and carat weight, explored in further detail below, all play a part in the grade and appearance of your diamond.

COLOR

High-quality diamonds are graded on the lack of visible color.  Truly colorless diamonds are rare, but diamonds with very slight traces of yellow or brown–the D-E-F range of the diamond color scale–are so close in appearance that they are referred to as “colorless”.  Diamonds in the G-J range on the color scale, appropriately termed “near colorless”, may still appear untinged to the naked eye, but are more common and typically less expensive than colorless varieties.

Further along the scale beginning with K color diamonds, the yellow/brown tint becomes more apparent.  Diamonds on this range of the scale tend to be set in yellow gold rather than a contrasting lighter metal.

The diamond color chart below can be used as a rough guide to each color range, keeping in mind that lighting and metal setting will also influence the color appearance of your diamond:

 

CLARITY

Like a perfectly colorless diamond, a perfectly clear diamond is a rare if not impossible find. But like color traces, slight imperfections affecting clarity–referred to as “inclusions” inside a diamond and “blemishes” on its surface–are undetectable in high-quality diamonds without powerful magnification.

The diamond clarity chart below illustrates:

FL (Flawless) and IF (Internally Flawless) diamonds show no inclusions even with a 10x magnifier, while VVS1 and VVS2 (Very Very Slightly Included) diamonds contain inclusions that are possible but difficult to spot under the same magnification.

More common are VS1/VS2 (Very Slightly Included) and SI1/SI2 (Slightly Included) clarity diamonds. Inclusions in these stones are easier to spot under 10x magnification, but still nearly invisible to the naked eye.

The lowest clarity gem-quality diamonds are rated I1/I2/I3 (Included) and contain more visible inclusions, even without the aid of magnification.

CUT

Of all a diamond’s qualities, it’s the cut that gives a diamond its distinctive sparkle.  While “emerald cut”, “oval cut”, etc. are widely understood terms for gemstone shape, “cut” in the 4Cs sense actually refers to a diamond’s proportions and how they interact with light striking the diamond.

The “sparkle” from light on a well-cut diamond is actually a combination of three effects: brightness, created by light reflections within the diamond and on its surface; fire, referring to the light bent into splashes of color within a diamond; and scintillation, the pattern of light and dark that seems to move and shift as the light changes. A polished, proportioned, symmetrical diamond will display a dramatic array of all three.

An ideal diamond is cut neither too shallow nor too deep. Light striking a shallow cut diamond will escape the diamond without refracting back to the viewer, giving the diamond a dark cast. A diamond cut too deep will refract light away from the viewer, making the diamond appear dull and flat. An ideal cut diamond will refract light between facets and back to the viewer, producing a bright, lively sparkling appearance.

 

 

CARAT WEIGHT

The term carat is often misunderstood. It refers to a diamond’s weight, not its size. Another misperception is that a larger carat weight is always better than a smaller carat weight, carat weight is not related to sparkle. Sparkle is the result of a well-crafted cut. In fact, a high carat weight diamond with a poor cut may look smaller than a diamond with a smaller carat weight and a very good cut.

The most familiar and intuitive measure of diamond quality, the carat (ct) is equal to 0.2 grams, or roughly 0.007 ounces. Under 1 carat, weights are often expressed in “points”, with each 0.01 ct increment equal to one point (e.g., 0.75 ct = 75 points). As rarity plays a stronger part in diamond cost than amount of substance, with larger diamonds much rarer than smaller diamonds, two otherwise identical diamonds may vary wildly in price even within a few points’ weight difference. The term carat comes from the ancient method of weighing precious metal and stones against the seeds of the carob tree—which were considered to be even in weight. It wasn’t until 1907, at the Fourth General Conference on Weights and Measures, when it was agreed upon that one diamond carat would be equal to 200 mg, or .2 grams, of a diamond. Carats can also be measured in points; 100 points equals a full carat.

Certain settings can make a diamond appear larger. A very popular setting to achieve this effect is the halo. This setting has a ring of small diamonds around the center stone. The ratio of the small to large diamonds skews the perspective in your favor, making the center diamond seem larger.

Carat Total Weight (CTTW). Total carat weight is the measurement of all the diamonds in any given piece combined. So, be sure to inquire about the weights of the individual diamonds in any piece that you are buying.