How do the Labs (GIA, AGS) measure diamonds?????

[Maxine]

There has been a bit of discussion here about discrepancies between different Sarin machines, etc....and often the Sarin measurements differ (usually very slightly) from the measurements on the certs......How do the labs take their measurements of the stones....? Do THEY use a sarin??? On the whole, how accurate are they????

Just curious...................

 

[denverappraiser]

They use Sarin (or OGI or Helium).

The variations you see have to do with the different callibration of the tools and the inherent margin of error in the equipment. For example, if you are measuring a distance with a tape measure and you really want to be as accurate as possible, you need to know the limitations of your tape measure. Most are marked to 1/32 inch or so but if you really try to declare the size of your house to this kind of accuracy you are asking for trouble. If you had several people measure your house, even using the same tapemeasure, they would almost certainly come up with slightly different answers.

Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver