Clarity standards for colored gems are quite different from those for diamonds. Learn how gem dealers grade clarity for colored stones like ruby, sapphire, emerald and aquamarine.
In the world of diamonds, clarity is one of the four "C's" that determine value, along with color, cut and carat weight. Diamonds are strictly graded for clarity on a scale devised by the Gemological Institute of America (GIA), from IF (internally flawless) to VVS1/VVS2 (very, very slightly included) to VS1/VS2 (very slightly included), and so on. Even very tiny inclusions can significantly lower the value of a diamond.
Clarity is also important in colored gems, but the standards are quite different. Applying diamond standards to colored stones would be a mistake, and would result in a buyer missing out on many fine stones. In colored gems it is color that is paramount, and inclusions are tolerated if they don't detract from the beauty of the stone. Indeed for gemologists, the presence of distinctive inclusions in a colored gem is essential in order to certify the stone as natural.
There is no international standard for grading clarity in colored gems similar to GIA's International Diamond Grading System. However, GIA has introduced a clarity type system for colored gems that helps consumers to understand that there are different clarity standards for different gem varieties. The GIA system classifies gem varieties according to 3 types:
Type 1 gems are usually found virtually inclusion free in the market. High quality specimens of Type 1 gems would have only tiny inclusions that could only be detected under 10x magnification. So when when selecting a Type 1 gem, a buyer should expect the gem to be almost loupe clean. Type 1 gems include aquamarine, morganite, yellow beryl, chrysoberyl, kunzite, danburite, smoky quartz, blue topaz, blue zircon, white zircon and tanzanite.
Type 2 gems are usually found with inclusions and a high quality specimen would be eye clean rather than almost loupe clean as in the case of a Type 1 gem. Type 2 gems include apatite, alexandrite, corundum (ruby and sapphire), diopside, fluorite, garnet, iolite, peridot, most quartz varieties (such as amethyst and ametrine), spinel, most tourmaline colors (with the exception of green, e and watermelon) and red, yellow and orange zircon
Type 3 gems are almost always found with significant inclusions. Even high quality specimens will have inclusions that are visible to the naked eye. Type 3 gems include emerald, red beryl, idocrase, benitoite, kyanite, prehnite, sphalerite, sphene and watermelon and rubellite tourmaline.
These functional grading terms tell you what you can expect to see when viewing the gemstone. They don't, however, tell you whether the particular stone is a high grade specimen. For that you need to consider other attributes of the gem, especially its color and cut. And you should always consider whether the particular gem is a high grade specimen of that particular type. The GIA clarity types help you understand whether some inclusions should be expected, even in high grade stones.
