1. Myth: Higher color or clarity grade in a loose diamond means it is more brilliant. Reality: Brilliance, or the amount of light reflected in the diamond, is not affected by the clarity or color grade of the stone. The color grade refers to the amount of yellow discoloration in the stone, while the clarity grade refers to the size and number of imperfections in the diamond. In most loose diamonds, the clarity or color grade of a diamond would have to be very low for the visible brilliance, or sparkle, of the jewelry to be affected. Cut is the single most important factor influencing brilliance. Also, once a loose diamond is set in a quality engagement ring setting, it will look more brilliant as well.

2. Myth: Carat weight defines the size of a loose diamond. Reality: Carat weight is simply the weight of the diamond, while the visible size of the stone will be affected by the depth of the cut. For example a stone with a relatively shallower cut will look larger than a stone of the same carat weight but a deeper cut. However, an extremely shallow or deep cut will drastically reduce the amount of light reflected in the stone and lower the value. It may be harder to see when the loose diamond is set in an engagement ring, but a certified loose diamond should always come with documentation about its exact proportions.

3. Myth: Yellow loose diamonds are more valuable than colorless diamonds. Reality: A diamond with a low color score (lower than a K) may be visibly tinted yellow, but such a diamond would have a significantly lower value than a true colorless diamond. “Fancy colored diamonds” is the industry term for yellow (and other colored) diamonds that have a bright, aesthetically-pleasing tint and a high level of brilliance. Some fancy colored diamonds are indeed more valuable than comparable colorless diamonds. Fancy colored diamonds are available in yellow, pink, blue, black, and brown, as well as other rare shades.

4. Blue fluorescent diamonds are more rare and therefore worth more. Reality: Although blue fluorescent diamonds are rare, they are not worth more than other kinds of diamonds. Blue fluorescence is a faint tinge of the kind of blue reflection to UV light that makes a white shirt glow blue under a UV light. A slight amount of fluorescence in a diamond can hide an unwanted yellow tint, although if the fluorescence is too strong it can make the diamond appear cloudy. When you buy a certified loose diamond, the accompanying documentation will attest to the level of blue fluorescence in the stone.

5. Myth: Diamonds are the most rare stone in the world. Reality: Although jewelry-grade diamonds are quite rare, comprising only 20% of all diamonds mined, they are still not the rarest mineral. Painite, a red or brown-colored mineral, is often considered to be the world’s rarest mineral, with only eighteen known specimens as of 2005. However, diamonds are the most valuable and sought-after jewelry stone, used in millions of designer engagement rings every year.