Colored Gemstone Clarity Scale
The gemstone clarity scale is based on white diamonds rather than colored gemstones. For colored gemstones, it is difficult to use a 'one size fits all' classification system for clarity, since some colored gemstones are expected to have inclusions and are sometimes even identified by their inclusions. For example, the inclusions of emerald often provide evidence that it is natural. Additionally, some inclusions are desirable, such as 'horsetail inclusions' in demantoid garnet and rutile 'silk' in sapphire.
The colored gemstone clarity scale depends on the type of gemstone. Since colored gemstones vary so greatly, GIA (Gemological Institute of America) classifies colored gemstones as either 'type 1', 'type 2' or 'type 3'.
Type 1 gemstones include aquamarine, yellow and green chrysoberyl, heliodore, morganite, smoky quartz, spodumene, tanzanite, green tourmaline and blue zircon. These stones are usually 'eye clean', meaning that no visible inclusions can be seen with the naked eye.
Type 2 gems include amethyst, ametrine, andalusite, alexandrite, citrine, corundum (all sapphire and ruby), garnet, iolite, peridot, spinel, tourmaline that is not green, pink or watermelon, and zircon that is not blue. These stones are usually included, which means that some eye clean stones can be found, but in lesser amounts than type 1 stones.
Type 3 gemstones are gems such as emerald, red beryl and red, pink and watermelon tourmaline. For a type 3 gemstone, an IF clarity rating is incredibly rare, since these stones are almost always included.
- First Published: April-04-2006
- Last Updated: September-08-2014
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