Valuing Gemstones

lab-appraisal-kimI wonder if people understand how I come up with appraisal values. I do more than guess at them. Most appraisers do. We should have a clear understanding of gemology, the science of first identifying, then grading gemstones. 

Every gemstone has a set of value factors. The most commonly known set of value factors is the diamond’s 4 C’s. These are cut, clarity, color and carat weight. Almost anyone who has ever purchased a fine diamond is familiar with them. Jewelry appraisers live and breathe these value factors. As one factor decreases, so does the value of the diamond.

Colored stones have some of the same value factors. Appraisers consider clarity, cut, carat weight and color, just as in diamonds. However, with colored stones there are also other factors including phenomena, like a cat’s eye or color change or adularescence.

Appraising colored stone jewelry is more nuanced than appraising diamonds. Consider color for a moment. An emerald is not just green. It may be yellowish green, which would reduce the value. Or it may be bluish green, which would increase the value. If the emerald is too light or too dark, the appraiser reduces the value. If the emerald has gray in it, that too reduces the value of the emerald.

Clarity grades in colored stones are different for each colored stone. For example, sapphires are expected to be eye clean. The appraiser should reduce the value for a sapphire with visible inclusions. On the other hand, the emerald is expected to have some visible inclusions. Moonstone is expected to be translucent. Lapis is expected to be solid. The appraiser should know how to grade for clarity in each of the different colored stones.

Quality of the cut is more important for diamonds than colored stones. Diamonds are cut for maximum brilliance these days. Colored stones are still often cut to maximize carat weight. There are exceptions. Some stone cutters create exceptionally beautiful gemstones by cutting for maximum color, clarity, liveliness and luster. Again, it is the job of the jewelry appraiser to recognize these exceptional gems and value them appropriately.

Pearls have their own value factors. These are size, shape, color, luster, surface quality, nacre quality and for a strand, we add matching. It makes sense that these value factors are so different from the others discussed above because pearls are an organic gemstone. I took a separate class at the GIA to learn how to grade pearls. I’m very happy I did because I appraise pearls frequently.

This is a short explanation about how the appraiser considers value factors when writing jewelry appraisals. If you have any specific questions, give me a call. I enjoy being the jewelry expert!!