The Four C’s: Carat, Cut, Clarity, Color
Carat: Diamonds are weighed in what is called a metric carat. One carat is equal to 0.2 grams, about the same weight as a paperclip. Like all things in the metric system, a carat is divisible by tens. A carat is divided into 100 points. For example, a 50-point diamond weighs 0.50 carats, which is also the equivalent of 0.1 grams. The majority of diamonds used in fine jewelry weigh one carat or less.
Cut: Though extremely difficult to evaluate, the cut of a diamond has three attributes: brilliance (the total light reflected from a diamond), fire (the dispersion of light into the colors of the spectrum), and scintillation (the flashes of light, or sparkle, when a diamond is moved). An understanding of diamond cut begins with the shape of a diamond. The standard round brilliant is the shape used in most diamond jewelry. All others are known as fancy shapes. Additional fancy shapes include the marquise, pear, oval, emerald, heart, princess, radiant, and cushion cut. See the chart above to view the various shapes.
Clarity: Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value.
- Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10× magnification
- Internally Flawless (IF) - No inclusions and only blemishes are visible to a skilled grader using 10× magnification
- Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10× magnification
- Very Slightly Included (VS1 and VS2) - Inclusions are minor and range from difficult to somewhat easy for a skilled grader to see under 10x magnification
- Slightly Included (SI1 and SI2) - Inclusions are noticeable to a skilled grader under 10x magnification
- Included (I1, I2, and I3) - Inclusions are obvious under 10× magnification and may affect transparency and brilliance
Color: Diamonds are valued by how closely they approach colorlessness – the less color, the higher the value. The scale for diamond color ranges from D to Z, with the majority of stones falling in the D to H range. Most diamonds found in jewelry stores run from colorless (D) to near-colorless, with slight hints of yellow or brown.