Presidium Instruments Gem Tester II (PGT II) Now with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones

This tester clearly displays hardness of all types of gems in all types of settings. It quickly clears up any mysteries about the gem at hand. Highly recommend!

This is my second Presidium gem tester. It is easy to use, although sometimes the calibration can be tricky. I have found that if you let the unit warm up for at least an hour, it minimizes the need for re-calibration. I use if for my vintage jewelry hobby.

This item pays for itself. It identifies counterfeit items. It identified a bunch of stuff from ebay and consignment stores.

Bought this for my wife to use to check out all her jewelry. She discovered one piece is not a gem but colored glass! It took us a couple of times to calibrate it, but we did it successfully. Not sure what these kinds of things should cost, but it seems overpriced to me... but it's a supposed precision instrument so maybe it's not overpriced. It's certainly not industrial grade equipment, but good for the jewelry collector/reseller/buyer. Comes with a nice case. Seems to be more accurate and capable than the pens you can buy for a lot less money.

Not well made. It worked reasonably well, although readings were somewhat inconsistent. It was a decent first screening tool. Then one day, after very limited use, the needle stopped moving. Almost $300 wasted! Buy something else!

Works great. A must for my Ebay business.

It worked as designed but you have different choices for gems and have to figure out which of those it is based on color. Since many gems can be different colors I couldn’t really figure it out. I know many people that use this tester and like it but it wasn’t for me.

I am learning to use this gem tester, I purchase several vintage items and needed this instrument to confirm what the sellers of these jewelry items are wht they state they are. Further, I had to return the first unit as I did not think it was working properly nor did it have a user manual, and it looked used. Seller shipped via FED EX an exchange in record time, that to me was very impressive and showed that they care! Meanwhile I was able to download a user's guide and its been most helpful! Thank you 'FindingKing' for your excellet customer care, I appreciate you very much.