Importance Of Inclusions

Edward Gubelin and John Koivula are considered god fathers of inclusion studies + their views should be an inspiring note (s) for newcomers in the field of inclusions studies.

Edward Gubelin / John Koivula writes:

From the tiny grains of beach sand the pebbles under out feet…to the glittering gemstones found decorating museums worldwide…..they all have something in common. They have a story to tell. The story of earth formation.

Through the microscopes this story unfolds as the kaleidoscopic world of gemstone inclusions comes to life. Solid crystal inclusions, glowing under polarized light, blink and change color as their host is turned in the field of view. Trapped in voids of crystallization called negative crystals, gas bubbles, propelled by thermally generated convection currents, shrink, swell, and even disappear as they dance about in small volumes of liquid, millions or even billions of years old. These solid and fluid inclusions, together with such additional internal features as twinning, cleavage, fracture, zoned growth and strain, like the components of a complex puzzle, help inclusionists to piece together a gemstone’s life history.

The study of gemstone inclusions is a fascinating and highly educational tangent in the field of gemology. A great deal of information on the paragenetic birth of a host gem can be learned from a single microscopic inclusion. Often times, to a trained eye, an internal inclusion pattern will yield valuable information on the physical and chemical environment of the host at the time of its growth. This will lead in turn to a greater knowledge of that particular type of gemstone deposit, and other localities at which the host has been found. Information on gemstone environments gleaned from the study of inclusions may lead eventually to the discovery of new gem deposits.

In many cases, inclusions in certain gemstones from particular localities are characteristic for that gemstone and locality. Natural and synthetic stones can often be identified by their characteristic inclusions. Many possess inclusions common only to them. If these inclusions are recognized the gem can be identified and often times, if natural, even the locality may be determined.

Mineral formational sequences at a particular locality may also be learned from a study of the inclusions found in the gems from that locality. Thank to research work on crystal and fluid inclusions, one can for instance exactly identify the inner and outer generational paragenesis of quartz from alpine clefts, of emeralds of hydrothermal origin from Colombia, and of metamorphic rubies from Mogok in Burma.

Since the advent of synthetic materials in the gemstone market, inclusions have been playing a major role in the field of gemstone identification. This role is becoming increasingly important as new and better synthetics, simulants and treatments are discovered, commercially developed and placed on the market. However, in spite of their importance, many gemologists still consider inclusions as undesirable flaws, and do not recognize the true beauty of mineral inclusions or the important information they provide.

In the world of gemology, thousands of dollars may hand in the balance where the identity of an inclusion pattern as to natural or synthetic—or even as to its source—is the only deciding factor. A knowledge of inclusions is vital in the jewelry industry today.

The gemologists of the future will be greatly dependant on a very strong knowledge of inclusions. As the synthetic materials become more sophisticated, and the laboratories find that they can duplicate nature very closely, the microscope will become the gemologist’s first line of defence, and a sound working knowledge of the various types of inclusions in gems will be of utmost importance.