Diamond appraisal is the process of having a stone inspected by a trusted appraiser who determines the stone’s retail value. Appraisals are very helpful for insurance purposes. During the inspection, appraisers look at the 4 C’s (color, clarity, cut, and carat) of a diamond in order to formulate a value estimate.
All other qualities being equal (clarity, cut and carat), diamonds that possess absolutely no color are appraised most highly. This is because of their ability to act as a prism, reflecting all colors of the rainbow in light. A diamond’s color is determined during appraisal using a scale ranging from D to Z. A score of D indicates that a diamond is completely colorless while a Z-rated diamond contains a yellow-brown tint. Appraisers most often use master diamonds with proven colors to determine where a diamond falls on the color spectrum.
The clarity of a diamond is determined based on how many blemishes and imperfections it has. Appraisers use a special scale to determine a gem’s clarity. Diamonds with “flawless” (or IF—internally flawless) clarity have no visible internal blemishes or “inclusions” when examined through a magnifying lens. Other rankings include VS (very slightly included) and SI (slightly included). Clarity is determined based on how many blemishes a diamond has, where those blemishes are located and how large they appear. Appraisers assign higher value to diamonds that exhibit greater clarity.
Cut refers to a diamond’s proportions and facets and how attractively those components reflect light. Out of the 4 C’s, cut is the only one that relies on a diamond cutter to determine its degree of integrity. In an appraisal, the proportions of a diamond are compared to those of stones considered to have the most beautiful or reflective cut. Shape is also considered during diamond appraisal, with greater value given to round diamond.
A diamond’s carat is its weight, with one carat equaling 0.2 grams. A diamond’s weight often correlates with its value; heavier diamonds carry a higher value than lighter diamonds. However, appraisers look at all four C’s to determine a stone’s value, so a larger size does not necessarily guarantee higher worth.