Answer:

• Clarity
• Color
• Cut
• Carat Weight

Clarity: Clarity refers to a stone's relative position on a flawless-to-imperfect scale. Clarity characteristics are classified as inclusions (internal) or blemishes (external). The size, number, position, nature, and color or relief of characteristics determine the clarity grade. Very few diamonds are flawless, that is, show no inclusions or blemishes when examined by a skilled grader under 10X magnification. If other factors are equal, flawless stones are most valuable. Click here for more information on Clarity Grading.

Color: Grading color in the normal range involves deciding how closely a stone's bodycolor approaches colorlessness. Most diamonds have at least a trace of yellow or brown bodycolor. With the exception of some natural fancy colors, such as blue, pink, purple, or red, the colorless grade is the most valuable. Click here for more information on Color Grading.

Cut: The proportions and finish of a polished diamond are its cut, or make. Cut can also mean shape, as in emerald cut or marquise cut. Proportions are the size and angle relationships between the facets and different parts of the stone. Finish includes polish and details of facet shape and placement. Cut affects both the weight yield from rough and the optical efficiency of the polished stone; the more successful the cutter is in balancing these considerations, the more valuable the stone will be.

Carat Weight: The metric carat, which equals 0.200 gram, is the standard unit of weight for diamonds and most other gems. If other factors are equal, the more a stone weighs, the more valuable it will be.