Color
Diamonds range from colorless, the most valuable, through rare "fancy" colors of yellow, pink, blue, green and others. There may be only a slight tinge of body color in the diamond but may very well affect the quality and price.
Carat-Weight
Diamonds are weighted in carats and increments of a carat that are called points. One hundred points are equivalent to one carat; fifty points to one-half carat; twenty-five points to a quarter carat. The larger the diamond, the more rare and therefore more valuable.
Clarity
Clarity indicates the degree to which a diamond is free from inclusions. Inclusions are characteristics showing that the diamond is of natural origin. A flawless diamond is very rare and therefore more valuable. The physical size, quantity, location, type and color of inclusions within the diamond are what separate each grade.
Cut
This indicates the physical shape of the diamond and how well it is proportioned. A diamond cut too shallow or too deep does not take best advantage of reflecting light back through the top of the stone. A well-proportioned diamond allows the greatest fire and brilliance.