Gemstone Classification on the Basis of Clarity
Where colored stones are concerned, categorization on the basis of clarity is a little different from diamonds. In an earlier post we discussed various clarity issues related to colored gemstones.
The GIA divides colored stones into three types – Type I contains eye-clean gems, that is, the ones with inclusions not visible to the naked eye, Type II is for gems that have a little more visible inclusions, and finally Type III gems are so included that they are rarely eye-clean. The type is characteristic any particular gem and is closely related to its origins. Emeralds are generally of the third type, and absence of visible inclusions generally arouses suspicion regarding the gem’s authenticity.
Now the important thing to note here is that the same description regarding flaws means different things with reference to different types. So, according to the GIA standards, a gem is graded as:
- ‘Eye Clean’ if no inclusions are visible to the naked eye for both Type I and Type III
- ‘Slightly Included’ if minuscule inclusions are present, visible with difficulty to the naked eye in case of Type I and in case of Type III, if they are apparent to the naked eye
- ‘Moderately Included’ if minor inclusion are present, easily visible to the naked eye for Type I and correspondingly, if inclusions are very apparent to the naked eye for Type III.
- ‘Heavily Included’ if, for Type I gems, inclusions are noticeable and affect its beauty, and for Type III, if the inclusions negatively affect its beauty and durability
- ‘Severely Included’ if inclusion are very noticeable and severely affect its beauty in case of Type I and if the inclusions affect the beauty and durability or both in case of Type III gems.
We have here a list of all colored stones with the clarity grades that they generally are found in. Remember that this is the normal trend and exceptions are possible
