Comet Tail Inclusion in Topaz: It looks like a comet flying through a gemstone. Instead it is a tiny crystal of an unidentified mineral that started to grow on the surface of a much larger topaz crystal. The tiny crystal made it difficult for the topaz below it to grow properly - it had become an obstacle to growth. As the topaz crystal expanded, it pushed the tiny crystal in the direction of growth, and a wispy stream of inclusions within the topaz was the result.
A microscope is one of the most commonly used tools of the gemologist. They use microscopes to grade gemstones, identify gemstones, separate natural gems from synthetics, determine the probable country of origin of gems, and learn how gems have formed. They also use microscopes to examine the quality of cutting and polishing done on a gem, and check gems for potential damage.
In this article you will see interior views of a variety of gems. Instead of focusing on the surface of the gem, we will lower the focus to look at their transparent or translucent interiors. Several of these views show features that gemologists use to identify synthetic gems. If you have never looked at the interior of gems with a microscope, several will be interesting inclusions or foreign objects that you never realized were hiding in your gems.