In their day-to-day careers, gemologists all over the world have to rely on a suite of precision-based instruments to help them identify and separate different varieties of gemstones. Here, we'll be introduced to the foremost essential equipment that every gemologist needs to adequately perform his tasks in the industry.
1. Gem Tweezers - Depending on your gemstone, you may want to use either titanium, stainless steel or bamboo tweezers for handling and sorting. This is because each gemstone possesses a 'hardness' property which can be described as a material's resistance to scathing or scratching. Some stones like diamond have a very high hardness (10), while other gems like pearls possess a much lower hardness (3 to 4). These numbers belong to a range called the Moh's scale, which is used in many other industries as well. It is very important to use the proper tweezer material so as not to damage your items.
2. A Fully Corrected 10x Triplet Loupe - This very essential tool is especially important in the diamond industry, because most 'colorless' diamonds are graded for clarity levels using ten times magnification only. Be sure that the loupe you purchase is corrected for chromatic and spherical aberration. If not, you may see color distortions and linear anomalies in some viewing areas.
3. Microscope - If a loupe doesn't allow you to properly view some interior areas of a gem, this next instrument will do the job much better. Gemologists' microscopes are quite different from the ones used in other fields of science (like microbiology). The gemological version is usually a binocular type (or trinocular for those with photomicrography needs) with a rolling zoom capability of somewhere between 10 times to 64 times magnification. Most laboratory setups require the microscope to view and assess inclusions within a specimen. The nature of an inclusion can help differentiate a gemstone from others that imitate it. These little bits of evidence also help to distinguish if a stone is treated, synthetic or natural.
4. Refractometer - The gemological refractometer is a small instrument that shoots light through a gemstone material in order to eventually show you the value of its refractive index. This trait is the measure of how much light bends and/or slows when it travels from one material (air in this case) into another (your specimen). Different mineral species possess specific ranges or values of refractive index, and so it is definitely a property that can help identify a certain stone's identity.
5. Polariscope - Each gemstone is classified as being either singly refractive, doubly refractive, aggregate material or amorphous material. The polariscope helps determine which by directing polarized light through your gem material as you rotate it 360 degrees atop a platform. Now, depending on the gemstone's identity, it can blink from light to dark, remain light or dark, display snake-like bands, or even show evidence of interior strain. This essential piece of equipment helps gemologists to narrow down the possible list of identities a gem could fall under.
Multiple Tests Often Need to Be Performed in Gem Identification, So As to Avoid Quick Assumptions and Mistakes.
In part 2 of this article, we'll introduce you to five more instruments that many gemologists keep in their laboratories or offices. These essential tools might also be able to help you acquire a better understanding of the gemstones and minerals you deal with everyday.
