Select a clean specimen stone, place it in the tips of gem tweezers, lift a 10x loupe up to one eye, and keep both eyes open. Move the specimen towards the loupe instead of moving the loupe back and forth until the stone’s surface is in focus. Doing this simple exercise instantly reveals the key concept behind how to use a loupe to examine a stone: keep your eye and the loupe still while you move the specimen to the proper working distance.
Positioning the loupe several centimetres from your eye gives you a small, unstable field of view. Your hand becomes a blurry blur as you search for the point of focus, the image wobbles, and any useful information is lost with the slightest movement of the specimen. Hold your loupe arm in a comfortable position, such as braced against your cheek or forehead, and bring the tweezers closer to the point that you can have one hand touch or brace the other. This close positioning minimizes any shifting and allows easier viewing of a facet junction, inclusion, fracture, or scratch area.
Light should come from an angle to illuminate the stone but never shine into your eye. Diffuse white light is ideal for a first look, but a small spot of direct light can help to reveal polish traces, chips and surface reaching features. Keep rotating the stone between the tweezers and avoid twisting your head or moving the loupe. Watch the reflections moving around the facets as the light source bounces off the different surfaces. Any internal feature should remain in the same part of the specimen no matter how its appearance may change.
Try to focus on one level at a time. Start at the surface of the stone and look at the polish quality, facet edges, scratches, stains, and any evidence of wear. Then shift the specimen a bit closer or further away to look below the surface. Just a tiny movement of the stone can shift the focal plane from the table facet to an inclusion deep within the gem. Trying to get the whole specimen in focus at once can result in general statements and overlooked details. Glass, mineral specimens, and synthetic gemstones are good practice tools for developing control before working with more valuable specimens. Pick out a specimen and look at the same area over and over.
Wipe it down with a lint free cloth, focus on it, look for one identifiable feature, lower the specimen, and repeat. You could even mark where the feature was located relative to the facet boundaries. Seeing the same location over and over builds steadier placement of the loupe and allows you to tell if a feature is permanent or if it was just a speck of dirt or a shifting reflection. One good test is if you can hold the view long enough to accurately describe what you’re seeing.
The phrase “there’s something in there” is not a detailed observation. Look again and determine if it’s round, angular, a thread, shiny, surface reaching, alone, or clustered with other features. Once you can consistently hold the loupe near your eye, smoothly move the specimen through the focus, and return to the same spot after turning the stone, your handling has developed to the point where you can proceed with more precise gemological investigation.
