The truth about diamond testers
A lot of people Including jewelers tend to rely on Diamond testers too much, which is understandable. Unfortunately testers at the time is insufficient tool, since modern technology of lab-grown diamonds and simulated diamond production are a few steps ahead of diamond testers modernisation. However the best proof is the official laboratory report from Laboratories like GIA, IGI, GCAL and others. Not your friend, nor independant appraiser will give you an accurate result.