inclusion plotting

[lucy]

just wondering-my GIA report only plotted one inclusion, a crystal; on the report-however on GOG''s site Jonathan points out three tiny ones in zooms. (thanks for giving MORE info rather than less GOG!) Does the GIA only point out stuff you can see thru a 10x mag or so and anything else there they DONT plot since maybe it would take a higher mag to see it? thnx

 

[dimonbob]

GIA only plots inclusions that can be seen at 10x under a binocular microscope with dark-field illumination and an overhead light. They do a search with higher mignification and turn down the power to 10x to plot. If it cannot be seen at 10x it does not get plotted. Those are international rules that the worlds labs agree upon. There has to be a cut off somewhere and they agreed upon 10x. If Rhino wants to take pictures of an inclusion that can only be seen at 20x, that is up to him.

 

[niceice]

If those of us who provide clarity photographs only did so at 10x magnification, nobody would be able to see anything on-line because of the resolution... So the pictures are usually taken at 40x / 50x / 60x / 70x magnification and thus more of the inclusions within the diamond are visible... As Bob has pointed out, the industry standard for diamond grading is 10x but let's face it, we'd all use higher magnification if it was available because it's so much more cool