As a GIA Graduate Gemologist (in residence at Manhattan), I'll answer for Mike (who said he was a "graduate" of GIA but didn't specify any credential/diploma): for the SI1 grade it typically depends on the stone and the person looking at it under daylight equivalent light. I advise my customers that the usual cutoff for "eye clean" diamonds - which means one can not see inclusions with the naked eye - is typically between I1 and S1 or SI2, but it depends largely on both the eyesight of the beholder and the lighting conditions. For instance, I'm extremely nearsighted, so without my eyeglasses I can read the microprinting on US currency that typically requires 8x power to clearly see, therefore many inclusions within most SI1 diamonds are readily apparent to me. That said, I always inform my customers that virtually no one will observe internal clarity characteristics - called inclusions - at the VS level and above without magnification. Finally, regarding the VVS1 grade, I always refer to the definition provided by the GIA (the world renowned authority non-profit school and gemstone grading lab that over 70 years ago established the diamond color grading system and the diamond clarity grading system): a VVS1 clarity grade means that it is "...extremely difficult for a diamond grading professional (Graduate Gemologist) to observe clarity characteristics" under 10x magnification utilizing a gemological microscope (dark field lighting). I hope you found this helpful.

Hey there! I'll break down the differences between SI1, VS1, and VVS1 clarity in the video, so stay tuned!