- Abrasion - A blemish, such as small nicks along the facet junctions.
A blemish, such as small nicks along the facet junctions (look whiter than the rest of the diamond), caused by impact damage. Excessive abrading often a sign that the stone is cubic zirconium, not diamond.
- AGS - American Gem Society - One of the leading gemological labs.
While DiamondWhisperer grades to GIA standards, AGS is quite close to GIA on grading standards.
See an exmaple of a AGS grading report .
- Appraisal - An estimation of value of an item, typically for insurance purposes.
While this might be a good guide for the layman, appraisals are rarely, if ever, up to GIA standards for grading purposes. Furthermore, appraisals provide an indication, usually exaggerated, of the retail replacement value of an item, not the re-sale value.
- Artificially Irradiated - See Irradiated Diamond.
- Asscher Cut - See Shape.