Discussing the anatomy of a colored gemstone is very similar to the discussion of a diamond. The parts of a gemstone are the same as a diamond. The crown is the upper part of a gemstone, just as the pavilion is the lower part. The carat weight is weighed the same.
Color is a bit different. When discussing color we are looking for consistent color throughout the gemstone. Some colored gemstones may have weaker colored tones on one side and stronger, more saturated tones elsewhere. A colored gemstone should have beautiful even color throughout the gemstone.
When grading the clarity, the diamond clarity chart can be used. There are gemstones where we expect to find inclusions and some we would not. Gemstones are separated by type. The type has much to do with the clarity of a gemstone. But more importantly the type of geological conditions that would allow the gemstone to be 'eye clean.' Clarity grades for gemstones are Type I, Type II, and Type III. So, the diamond clarity scale and the gemstone types are used together.
For example: A VS clarity gemstone under Type I will have minor inclusions that are somewhat easy to see with 10x magnification. A Type II gemstone with VS clarity may have noticeable inclusions under 10x magnifications. Type III gemstones will have inclusions that will be very easy to find under 10x magnification. All can receive a VS clarity grade.
Examples Type Gemstones :
- Type I Gemstones - Aquamarine, Manganite, Tanzanite, Green Tourmaline
- Type II Gemstones - Amethyst, Alexandrite, Citrine, Sapphire, Ruby, Garnet, Pink Tourmaline
- Type III Gemstones - Emerald, Red Beryl, Watermelon Tourmaline.
Although there are no specifications for the custom cut gemstones. Gemstone cutters are seeking to augment the natural beauty of any gemstone. Like a diamond, the cutter's job is to get the gemstone to reflect light in a brilliant way. And finally, the cutter will polish the gemstone to give each facet a reflective surface.