Colored gemstones are first judged by their color while diamonds are judged more for their cut and clarity. This is even more true with emeralds, rubies, and sapphires because they are seldom 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.  Most of the big three colored stones are cut with weight retention in mind rather than optimal light return. Generally commercial cut stones are polished to 14K diamond grit or less. American style faceting in contrast is usually polished at 50K diamond or higher. Modern oxides are in common use by custom cutters and provide a polish similar to 100K diamond grit.

One mistake that gemstone buyers make when looking at well cut stones is to be dazzled by the brilliance while forsaking the color. Don’t forget the color! The color should always be the first criterion to judge. Our eyes naturally gravitate to the sparkling stone on the counter but brilliance will make light colored gemstones appear better than they are. Turn the stone on its back or look at it from the side to get a better idea of the actual body color of the gemstone without the cut affecting your perception. Clarity and brilliance is important but should not trump color. Color is always the largest percentage of cost in any gemstone. After you’ve found a few gems with the best color then go and judge them for clarity, cut, and “fire”. You don’t need to sacrifice brilliance or clarity but it should not be the first thing to look at.