“Gemological stereo microscopes are meant to help with stone inspection and stone setting. These are more advanced in that they have an iris and darkfield condenser on the bottom light source, and usually a set of on stage tweezers to hold the stone in place.”
What is a gemology microscope?
A gemology microscope (or gem microscope for short) is a microscope typically used by jewelers, gemologists, and stone setters to perform the day to day labors of their careers. Gems and jewels, as many of us know, have a variety of grades (or quality levels) to them, which ultimately influence their value and cost on the market.
Also called GIA microscopes (Gemological Institute of America), these kinds of microscopes typically come with a stereo microscope’s version of a darkfield condenser, and a set of tweezers built into the base of the microscope to hold the sample in place. A GIA microscope is also a brand, though, as the GIA has specific guidelines on what a gemological microscope is required to have to be used in a professional or stone research scenario. GIA microscopes are generally very, very expensive, so it’s good to know what inexpensive yet quality options you have.
For lighting, these at minimum have a light coming from the base up, so a transmitted light, and a reflected light coming from above the stage as well–especially for stone setters. A bottom light does little good for a stone setter, and ultimately the purchaser of the gemstone is going to be seeing it from outside of a microscope (as are his/her friends, family, etc), so it makes perfect sense to want to view the stone’s surface as well as its interior.
So how does the darkfield condenser help view gemstones?
The darkfield condenser in this case is merely an iris. The iris is adjusted down to allow only a pinprick of light to penetrate the iris, and hit the gem. This illuminates the interior of the gem, showing fractures, inclusions, and other elements used to grade the stone. The iris also provides itself a dark background around the sample, so you have great contrast to help view the stone’s elements in great detail. It’s significantly more simple than a compound darkfield condenser!
What is an inexpensive gem microscope for gemology students, or hobbyist? I can’t seem to find one.
Unfortunately, gem microscopes at fair prices with quality are difficult to come by, especially those that fit GIA microscope standards. But, luckily for you, I do have a suggestion that a few acquaintances of mine ended getting and loving.
AmScope’s GM300TZ
The GM300TZ is probably unique in that for a full sized gemology microscope, it is a coordless model! So, add some batteries it the base of your microscope, and congratulations, you don’t need to plug it in anymore at all.
It uses the same SM head as the other stereo microscopes in AmScope’s stereo microscope line, so the differences are all below the shoulders, persay. The darkfield condenser with iris, the tweezers, the black stage illuminator housing, and the gooseneck external lighting coming from the unit all scream gemology microscope to me, and after seeing this, will to you too.
It also has the trinocular port to install a (sold separately from this package) USB microscope camera, to share pictures with customers online on a website, or via email. Very handy for the large volume jeweler.
For more pictures or information on purchasing this unit, you can find it here: AmScope’s GM300TZ