Diamonds are graded for clarity based on 10x magnification, so you don't always need a fancy microscope to check the quality of your precious stones. A handy loupe is sometimes most preferable, because during travel, trade shows, sales meetings or wherever you go, it's not very convenient to backpack your gemological microscope.
Gem Loupes are the Most Basic Viewing Instruments to Carry Around With You During Gemstone Buying Trips. They Are Helpful for Grading Diamonds, Identifying Colored Stones, and Even Checking Laser Inscriptions for Report Matching.
A gem loupe is usually made up of three lenses. These three lenses function together to give you the most accurate and undistorted image you can get at a specific magnification level.
We call this loupe a fully corrected triplet loupe. Others may sometimes call it an apochromatic loupe, which means it is both aplanic (corrected for spherical distortion) and achromatic (corrected for color distortion).
There are many "fake" triplet loupes out there that make use of a single lens. You'll notice that these instruments will show you a more distorted view of your gemstone, especially when you observe around the outer edges of the viewing area.
It's always recommended to familiarise yourself with how true gemological loupes showcase a magnified image, so that you know what to look for when buying a new or a replacement loupe.
Using your loupe correctly is also good practice. It shows professionalism, and at the same time makes it easier for you to evaluate stones with more comfort and patience.
To begin, unfold your loupe and use the side of your index finger and tip of your thumb to hold the lens case. Now position the lens in front of your eye (or eyeglass lens) and let the back of your thumb gently press against your cheek. This is just to keep your hand from fidgeting while you use your loupe.
So now, with your other hand holding your tweezers, gently pick up the gemstone properly. Bring the tweezers up to position their tips just in front of your loupe, while your hand's palm faces you. At the same time, use your loupe-hand's ring and middle fingers to steady the tweezers in position by grasping them. This way both your loupe and tweezers will only have minimal shaking while you work.
Don't forget that its best to open both eyes while using the loupe, even if only one eye is being used to work. This actually helps alleviate strain. Practice makes perfect.
