I1, I2 and I3 are the lowest clarity grades. Their inclusions are obvious at 10x and can affect transparency and brilliance.
In more detail
I3 is the bottom of GIA's scale. In our simulator, an I3 stone plots eight characteristics, against one at VVS1.
On a grading report
Written I1, I2 or I3 in the clarity grade line.
Related terms
- Slightly Included (SI1, SI2): SI1 and SI2 are the clarity grades for inclusions that are noticeable at 10x magnification.
- Clarity grade: The clarity grade says how free a diamond is of inclusions (inside) and blemishes (on the surface) at 10x magnification. GIA's scale has 11 grades in six categories, from Flawless (FL) to Included (I3).
- Cloud: A cloud is many tightly grouped pinpoints that are too small to see one by one but together look hazy.
- Feather: A feather is the general trade term for a break in a gemstone. It often looks white and feathery.