To the layperson, a gemstone is typically known by its color or general look, but a gemologist must use a more specialized method in identifying them. Gems that look alike can easily be mistaken for one another if only a visual inspection is given. To correctly identify them, gemological tools and gemological experience are necessary to get an accurate answer.
Gemstones are examined by basic characteristics such as color, transparency, luster and crystalline form, and the presence of visible inclusions or any other unique identifying features, which help the gemologist decide upon their identity.
Refractive index measures the amount that light passes through a gemstone, which is different for all minerals. It is a crucial component when identifying a gemstone because this is the property that causes a gem’s appearance and has become one of the most commonly used gemological techniques worldwide.
Another critical component in identifying gemstones is the use of magnification. When using a microscope or a loupe, the gemologist examines the characteristics inside a gemstone to determine its origin and formation. Natural features, inclusions and growth patterns are often the “identifying features” that help the gemologist identify the gemstones type and in some cases, whether it was formed naturally or in a laboratory.
A more detailed examination includes an analysis of the relationship between gems and light. Some gems may display certain optical properties, like double refraction, fluorescence and color changes, which provide clues in the identification process.
Hardness testing is used when identifying gems, but less often now. Because a gemologist must be careful to protect the stone, they now use non-destructive gemological techniques and equipment when possible.
With the use of modern technology and equipment, the analysis has become even more precise and accurate. Tools and equipment that test chemical composition, crystal structure and other laboratory techniques can help identify gemstones which may be very difficult to identify using traditional methods alone. In particular, synthetic gems that have improved in quality and appearance in the last few years, now require more technology to distinguish between natural and laboratory stones.
Regardless, gemological tools and equipment do not replace the need for human experience. A gemologist interprets information that instruments supply, using gemology experience to determine identity. A skilled gemologist is able to read different characteristics and recognize trends and patterns that could have been overlooked if only measured.
Gemstone identification is one of the most interesting features of a gemological degree. Each gemstone brings a new challenge to the gemologist to discover and examine. The process of identifying gemstones is one that combines all the skills of a gemologist, including science and observation, along with the drive to identify a gemstone’s identity. Accurately identifying a gem is the first step in a variety of grading, valuing and appraisal processes. It would be hard to determine a value without knowing whether a gem is authentic or real. Therefore, it can be a valuable skill for any gemologist to master.