High Accuracy Professional Diamond Tester Pen Jeweler Tool for Novice and Expert - Diamond Selector II 9V Battery Included(Black)

This is very accurate. A bit confusing on what number it should be on. It seemed that around 6 seemed to work for all diamonds sizes.Only negative is that the battery doesn’t seem to last all that long. Great product for the price!

Excelente producto se los recomiendo

Still works years later

The media could not be loaded. I inherited a lot of jewelry and I needed a way to see if it was all real or not. I used this diamond tester on around 25 pieces of jewelry that I already owned and it was 100% correct on all of them. I tested both large and small diamonds and as you can see in the video you need a steady hand for smaller diamonds because if it touches the metal you’ll get an inaccurate reading. You also need to frequently re-adjust the calibration because it can get too hot and mess up the reading. As long as you are able to eyeball the carat weight of a diamond, you will do just fine with this tester, in my opinion. If you don’t know what a carat, .5 carat “looks” like you should familiarize yourself because that’s the basis of the calibration. Instructions were clear and easy. I highly recommend.

This is very sensitive to temp which makes it kind of hard to calibrate. However, once it is calibrated, it seems to work well on everything but earrings (probably due to stud blocking electricity flow). I tested on known diamonds (rings/bracelets) and known fakes and it was accurate only after calibration (meaning use a known diamond to get it to temp and accurately reporting it as a diamond). I would not use this without calibrating each time you use it as it is very easy to get a false reading and that could be a costly mistake. (I did not test using loose stones and I would not trust this for that at all as it seems very sensitive).

This is a cheap tester and you get what you pay for here, it is not accurate. I work in a jewelry store and have access to a more expensive and as it turns out, much more accurate tester.This tester alerted 'diamond' on CZ, white topaz, and white sapphire (loose stones, so not touching any metal), but failed to alert on several real diamonds (that alerted on other testers and are independently certified).Not enough pressure and it won't alert on genuine diamonds, but too much pressure and it alerts on everything else and the difference between not enough and too much is a pretty small margin.The other positive reviews leave me to wonder if I just got a dud, which I hope is the case, but I would waste the time and money trying again on it.

Works great! You just have to do it on the flat surface of the diamond.

Great