Q:I bought diamond ear rings in costco. since they were less than 1CT, it came with costco certificate with GIA number. How do I check the validity of this GIA #. I could not find a report for that number in GIA website.
A: GIA is the Gemological Institute of America. It is the Institute that sets the standards for all gemstones, from Alexandrite, the price of which is ever so much higher than diamonds, to Zircon, not to be confused with Cubic Zirconia (a man made gem substitute).