Instruments Gem Indicator (PGI) Handheld Tester for Identifying Diamonds and Common Colored Gemstones

Excellent Seller! Purchase a Presidium gemstone tester! I love it! Thank you!

Great tester, as other reviews have stated You have to have some Knowledge of Gemstones while using this pen which I had no problem with, you can go on the Presidium Website and Download the Spreadsheet of Gems if you’re not sure. As far as Diamond if I wasn’t holding the pen straight and at an angle it would read Sapphire and Ruby, you need to hold the Tester at a straight angle to get an accurate reading, held straight tested for only Diamond. I just wish this one Included an option for testing moissanite!

It worked for less than a year. For the price point, it should be way better quality. It now reads “slip detected” constantly - even when it’s not against the stone yet. It’ll provide a reading before the tip has touched the stone. You can test the same stone twice to multiple different results. Save your money & buy any other machine to help you out.

This is a small, portable, convenient unit with moderate accuracy. When testing stones, you depress the probe and are provided a selection of colors to select. Once you’ve selected the color, the device will provide one to several options which the stone “could be”. You then have to make your best guess based on experience / comfort level. I’ve gone through a couple of these units in recent years and they tend to get a mind of the their own after a bit of use, and start testing “air” before the probe gets to the gemstone. Despite the function to calibrate the unit, it may take many, many attempts (while the unit believes you’re testing something) to actually apply the probe to the stone for a reading. It eventually gets to the point you’re unable to test anything because the unit will not stay in the ready mode long enough to apply the probe to the stone. If it happened occasionally to a single unit, I would not consider it an issue. Them same failure has happened to the two units I’ve purchased. There is not a wide selection of devices out there as alternate choices which are comparable, so I can’t say I wouldn’t buy another one. If I were to purchase another one, it’d be with the understanding it is a ‘budget-friendly unit’ with limited accuracy and lifespan.

I found this gem tester to be very inaccurate in that it gives you a wide range of possible stones. It also has a very difficult time with blue and green stones calling them glass most of the time. For the $300 plus price I expected it to be more accurate and informative. I have an RI tester that is so much better but is hard to use on smaller stones. That was my main reason for the purchase of the new tester with a small tip. It will press against small gems but the readings are not very accurate.

I found that when using this product, it works every single time, every gemstone that I used it on came back with the exact right name. Some people have been giving bad reviews about this product. I feel that they weren’t using it right, or didn’t read the instructions all the way that you have to download, or they need a new tip.

I was worried because of some of the other reviews but I got this product and it is an excellent diamond tester. It can also test some of my Amythyst and even showed me that a few family heirlooms were glass hahaha. It doesn’t say Cubic Zicornia but it will give you the same 8 options so you know what it means. And most importantly, if you test CZ, diamond will not be one of those options! I’m happy with it. Definitely recommend. It can test rubies and sapphires too.

Challenging to figure out… Did not seem accurate

Falto el instructivo y caja vino dañada tratare de bajar el manual de internet , medio difícil de utilizar

Keep the operating procedure simple to follow/understand. Can you share a detailed and simple procedure to start using including how to test different colored gemstones?