"As mounting permits" means that a lab graded a stone in its setting. The grader could judge it only as far as the setting allowed.
In more detail
IGI grades mounted stones this way. Color and clarity then become a range, such as D–E, with an estimated cut grade. GIA's diamond grading reports are for loose stones only.
On a grading report
On IGI reports for set stones.
Related terms
- Diamond grading report: A diamond grading report is an independent lab's record of what a stone is and how it grades. It is true for the day the lab examined the stone.
- Color grade: The color grade is a letter from D to Z for the yellow or brown tint of a near-colorless diamond. D is colorless and Z is light yellow or brown.
- 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).