Using the 10 X Hand Loupe, and HOW TO:

The simple hand loupe is the most valuable tool of the gemologist, or the serious buyer of gemstones. You can learn more about Emeralds, and with greater ease, than with any other instrument.

The Hand Loupe is the least expensive piece of equipment (as little as $15. u.s.) and fits easily into a pocket, purse or briefcase. Once you learn to use it, you will begin to see why it is called: "the Gemologist's Best Friend."

Ten-power magnification is the most useful. Higher than that, and the depth of field, (the area that remains in focus), is so small that the Loupe becomes difficult to use...

One of the terms used to describe a loupe is "triplet." That means that is has three lenses which eliminates distortion around the edges. Another feature offered in more expense loupes is a special lens coating for "color correction." The colors seen through the color corrected loupe are natural and not distorted.
Before focusing on anything, consider the light around you. To inspect the gems surface, to evaluate cutting and polishing, you will want the light shining down on the stone. If you are in a room with an overhead light, this is simple. If your best light source is a window, you will need to position yourself so the light is coming over your shoulder. Avoid having your shadow on the stone.

To see the inclusions in a gem you need the light behind the stone and shining through it. Often you can get to see both the surface and the interior of the gem with a minimum of adjusting. These two conditions are always easy to achieve with a little thought. The only limitation is having too little light to see well.

To focus, hold your loupe hand firmly against your cheek. Keep both eyes open, (this reduces eye strain,) and hold the gem in front of the loupe. Move it slowly toward and away from the loupe until the gem comes into focus. Then practice adjusting the focus from the top surface to the far side. On a small gem you can get the entire stone in focus at once. Larger gems require that you focus on one area at a time.