What is clarity of gemstones
The clarity of a stone is commonly described as being from "Free of Inclusions" over "Lightly", "Moderately", and "Heavily" included.
Here is how we describe a stones clarity:
- Free of inclusions: Either under magnification no inclusions become visible or only a pro with a lens might find an inclusion, but maybe not.
- Very lightly Included: Inclusions are visible under a 10x magnification but rarely with the unaided eye, almost no inclusion
- Lightly Included: One might see inclusions with the naked eye, but they should not dominate the stone, and after setting the stone appears better
- Moderatly Included: Inclusions are clearly visible and influence the stone's appearance, these include bigger black spots
- Highly Included: A stone might not be durable, and very unpleasant appearance
Magnification can be used to locate inclusions, but with the exception of inclusions which might impact durability, only those visible to the naked eye should influence the final grade. In this way, colored gems are very different from diamond. Indeed, in certain cases (Kashmir sapphires being a classic example), the inclusions can actually enhance beauty and value.
There are two key factors in judging clarity. These are:
Visibility of inclusions
Impact on durability
Note that cabochon-cut gems generally have poorer clarity than faceted gem. This is because inclusions are more visible in faceted stones than in cabs.