The choice is largely a matter of personal taste. Whatever your preference, a well cut diamond is the work of a master diamond cutter, since it is the cut that enables the diamond to reflect light, creating scintillation and sparkle. When a diamond is well proportioned, light is reflected from one facet to another and dispersed through the top of the stone as rainbows of color.

Every diamond regardless of its shape gets it brilliancy and scintillation by cutting and polishing the diamond facets to allow the maximum amount of light that enters through its top to be reflected and dispersed back through its top.

In a correctly cut, "Ideal cut" stone, if the angles are correct, the light that enters is dispersed properly back through the diamond's top facets. When a stone is cut too shallow or too deep the light that enters through the top is allowed to escape through the diamond's bottom and does not allow the maximum beauty of the diamond to be realized.

Carat

Carat is actually a measurement of weight, NOT size. However, it should be relative to size. One carat is divided into 100 points. 1.00 ct is equal to .20 grams. Two diamonds of equal quality can have different values depending on their cut, color and clarity.

Carat is the easiest of the 4 C's to determine. One carat is divided into 100 "points," so that a diamond of 75 points, for example, weighs .75 carats, 50 points weighs 1/2 carat etc. Fine quality can be found in diamonds of all carat weights. If a diamond is cut for beauty, and not maximum yield in weight, it is more desirable than a heavier weight and lumpier stone, and will have the appearance of a larger stone.

Color

Diamonds are found in a range from colorless to yellowish, and judged according to a color grading scale from "D", which is totally colorless through "Z" which is vivid yellow. It is the colorless diamond that is most valued because it is the most rare. The difference between one color grade and another is very subtle, particularly to the untrained eye. Although increasing shades of yellow reduce the value of a diamond, they do not necessarily reduce its beauty. If a diamond is well cut, its refraction and dispersion of light will often disguise certain degrees of coloration. The average stone bought carries an I or J grading for its Color. In addition to diamonds listed from D to Z, there are twelve other colors called Fancies, and as the name implies, they are expensive.

Clarity

Most diamonds contain tiny natural birthmarks called inclusions. Most are not visible with the naked eye but can be seen with 10X magnification. Inclusions interfere with the dispersion of light and therefore the diamond's brilliance. The fewer and smaller the inclusions, the rarer the stone and higher the price.

While inclusions do not generally affect the diamond's beauty and usually cannot be seen, their presence reduces the price. Clarity is graded on a scale with a range from internally flawless (IF), very very small inclusions (VVS1-VVS2), very small inclusions (VS1-VS2), small inclusions (SI1-SI2) to imperfect (I1-I2-I3) with eye visible inclusions.