A diamond with no color allows maximum light to pass through it, therefore this type of diamond is usually preferred for its sparkle. On the color grading scale, diamonds graded D, E, and F mean they have no color. G, H, and I diamonds have very little color. J, K, and L mean that the diamond is a slight yellow color. P, Q, R, S, T, U, V, W, and X diamonds have a darker shade of yellow. Diamonds graded Z has a color other than yellow or white and are the rarest and most expensive diamonds in the world. Generally, D-graded diamonds are the most valuable, and X the least.

The cut of the diamond refers to the shape it is cut into and also its reflective quality.

Diamonds are generally cut with 58 facets. The sparkle and brilliance of the diamond generally depends on its cut, its angles, its finish and its ability to reflect light. The most popular diamond cuts are heart, oval, marquise, princess, pear, trillion, round, and emerald. Common cutting problems include a diamond cut too thin that causes it to lose some of its sparkle, or a missing or off center culet.

The clarity refers to the diamond's internal and surface imperfections and blemishes. Diamonds that are clear are more brilliant; they are also quite rare and thus highly priced. These flawless diamonds have no internal or external imperfections or blemishes

The perfect diamond carries a grade of FL or IF, that is, Flawless or Internally Flawless. A diamond with a grade of I-1, I-2 or I-3 means that it is imperfect, with I-3 being the worst grade. VVS1 and VVS2 means that the diamond is very very slightly imperfect; VS1 and VS2 diamond is very slightly imperfect; and SI-1 and SI-2 means that the diamond is slightly imperfect.

The unit by which the weight of the diamond is measured by is called the carat. One carat is equal to 200 milligrams. A carat is divided into 100 segments called points, with 150 points equal to one and a half carats.

When you purchase a diamond, you must purchase a diamond certificate also known as the Diamond Grading Report. This report is issued by the Gemological Institute of America otherwise known as GIA. With this diamond certificate, you can verify the diamond's color, cut, clarity and carat. You can buy a diamond with confidence from the diamond dealer as long as the certificate is GIA-issued and not from the dealer. Do not accept certificates from any other institute other than GIA, as GIA has been established as the most trustworthy and respectable.