Metal Testing Clause: I do NOT have $12,000-$20,000 plus metal x-ray testing equipment. Metals are tested and stamps acknowledged. However if it tests 16.7 karat on a x-ray machine and I test weak 18kt and strong 14kt with acid testing I cannot know the exact metal content. Jewelry is not stamped 16.7kt. The Authenticity Guarantee program has sophisticated calibraized x-ray machines to test metals that I as a consumer buyer, seller, GG (GIA) cannot compete with. I've bought two, expensive electrical metal testing equipment items in my experienced career and have both that don't work. I trust good old acid testing for metals but cannot be exact as high calibrated e-ray machines.
Diamonds and Gemstone Grading: A GG (GIA) needs to be within 10% of carat weight, no more than one grade off either side when grading Color, Clarity in an Unmounted Loose Diamond or Gemstone. It's 20% up to 30% if Diamond or Gemstone is mounted. We work to be within 10% mounted but this is not practical nor required to be a GG (GIA). The GIA does not provide Carat Weight for mounted stones on GIA Reports. They must be removed from mount to have a carat weight provided.
The Authenticity Guarantee program requires consumer sellers to be within 10% for mounted Diamonds and Gemstones.
Thank you, Gems Jewelry and Diamonds