21st Guru

Colored gemstones are initially judged by their color and unlike diamonds not their brilliance or cut. This is particularly true with emerald, rubies, and sapphires since they are rarely cut with American style meet point faceting techniques. This technique uses diagrams where the facets meet at a point and produce the best light return for a particular species of gemstone based on the refractive index.  Almost all rubies, emeralds, and sapphires are cut commercially less concern for light return but rather maximize the yield of the expensive rough stones. Generally commercial cut stones are polished to 14K diamond grit or less. Most custom cut stones will be polished to a minimum of 50000 diamond grit. Newer aluminum or cerium oxides used by custom faceters come closer to a 100000 grit polish.

Although gemstones with meet point faceting clearly have a better cut over commercial stones there is a mistake I often see when people are shopping for gemstones. Don’t forget the color! The color should always be the first criterion to judge. Our eyes naturally gravitate to the sparkling stone in front of us but brilliance will make light colored stones look better than they are. Turn the stone on its back or look at it from another angle to get a better idea of the actual body color of the gemstone before the cut affects your perception. Brilliance or “fire” is important but should never outweigh color. Color is always the largest percent of cost in any colored gem. Once you’ve found a few gems with the best color then go and evaluate them for clarity, cut, and brilliance. You don’t need to sacrifice brilliance or clarity but it should not be the first aspect to look for.