Why do geologists have an easier time identifying gems than gemologists? Because they can more readily conduct destructive gemstone testing. Geologists can scratch gems to test their hardness, check their reaction to acids, and even put them in a torch’s flame to identify them.
These destructive tests are informative but, obviously, they damage the gems and reduce their value. Gemologists normally use complex optical and microscopic examinations to identify unknown gemstones without damaging them. Unfortunately, standard gemological tests occasionally fall short of positive identification. In these cases, gemologists must resort to destructive gemstone testing. With great care, however, these tests can be conducted in a limited manner without diminishing the value of the stone.
Our five-part series on destructive gemstone testing offers concise explanations of the principal procedures.