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๐ Unlock the secret life of your gems with precision and style!
The Presidium Instruments Gem Tester II (PGT II) is a compact, battery-powered thermal conductivity tester featuring the industryโs thinnest retractable probe tip and Assisted Thermal Calibration (ATC). It reliably identifies diamonds, moissanites, and 16 common colored gemstones with a clear analog dial, making it an essential tool for jewelry professionals and vintage collectors seeking accurate, on-the-go gemstone verification.






| ASIN | B08M87J44P |
| Best Sellers Rank | #112,619 in Arts, Crafts & Sewing ( See Top 100 in Arts, Crafts & Sewing ) #39 in Jewelry Diamond Testers |
| Brand | Presidium |
| Brand Name | Presidium |
| Color | Black |
| Customer Reviews | 4.1 out of 5 stars 418 Reviews |
| Item Dimensions | 4.5 x 3.8 x 7.8 inches |
| Item Weight | 0.54 Kilograms |
| Item dimensions L x W x H | 4.5 x 3.8 x 7.8 inches |
| Manufacturer | Presidium Instruments |
| Measurement Type | Thermal Conductivity |
| Model | PGT-II |
| Part Number | PGTII |
| Power Source | Battery Powered |
| Specification Met | Yes |
| Unit Count | 1.0 Count |
| Upper Temperature Rating | 27 Degrees Celsius |
L**Y
If you sell jewelry, this is a great tool
Have had this for a while now, still working perfect.
M**Y
Good item
Very good item. Competitively priced.
K**K
A must for vintage jewelry lovers.
Going through vintage jewelry this product is a must! It sure helps you correctly identify your stones. I love it.
J**N
Nothing but trouble
Has caused me nothing but Trouble. I have owned it for a year and a half and have only used a handful of times. First, the pen broke so I spent $80 on a new one. Then, the base wonโt calibrate and they want me to send back to Singapore, (I DONโT THINK SO). I gave it a 3 for easy to use because I never got to use it, probably only 5 times. DO NOT BUY!
R**R
Not simple to calibrate, but it works!
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.
V**Y
Great tester
GREAT TESTER !
M**N
Working Well So Far
I have only owned this tester for less than a month. So we'll see how things go over time. I haven't had any issues yet with the calibration (knocking wood). If you buy this, make sure to register your product right away so you can get assistance if your tester isn't performing as it should. I'm fairly inexperienced when it comes to gemstones, but I sell vintage jewelry (mostly costume) so I do come across items I need to identify from time to time. Honestly for someone like me, it's actually just great to be able to test older pieces and confirm whether I'm dealing with glass or a gemstone. I consider the tester to be a starting point for additional research, not necessarily the final word. I was pleasantly surprised to identify some pieces I own that I hadn't really assumed to be gemstones, or just didn't have a clue about the specific stone. But I can see the more likely scenario is that it will identify a stone as something like quartz, then I have to go do my research because that can encompass multiple varieties of stones. So if you consider this as a research tool and understand that you still have to go out and learn more information, this is a pretty good investment and will probably end up paying for itself.
K**.
Grateful to the Seller
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.
R**U
To know what stone it is and not glass.
Testing
E**N
Getting the exact name of the stones now leaving to guess
The presidium instrument gemstones tester is a good product. It would have been great if there where actual light to indicate the name of the exact stone instated of just a line with more the one name leaving you to guess what exactly it's.
B**E
Good when working correctly.
I like the variation this tester has for identifying various gems . However , I find the pen has been extremely finicky and I can hardly have it calibrate up to the Cal indicator level without constantly cleaning and wiping down the cal glass and pen tip. I may have received a faulty pen as it has play back and forth ?
L**A
It didn't work
This tester was broken, I only wasted time on waiting for it and the returning it.
A**R
Works but hard to tell exactly what gem it indicates
The categories are vague so follow up research is definitely needed. I tested a large 100% known-to-be amethyst and it miss read it completely, so that was quite disappointing. Hard to trust the readings after that fail.
Trustpilot
1 month ago
1 day ago