Garnet Inclusion Illusion

A cleverly designed “garnet in quartz” double cabochon represents a new and unexpected challenge for gemologists, collectors, and designers who intend to feature inclusion gemstones in their jewelry lines. This assembled inclusion consists of a fragment of pyralspite-series garnet sandwiched between two quartz cabochons (figure 1). The garnet and quartz were identified with optical and Raman spectroscopy, respectively, at GIA’s Carlsbad laboratory. While the specimen creates the illusion of being natural, clues to its artificial origin include air bubbles and the fragment itself, which shows neither crystal faces nor the rounded appearance of an etched or eroded crystal. Rather, it is a relatively sharp fragment that resides in a pocket filled with glue (figure 2). The subtle glue layer between the cabochons becomes more apparent when viewed under UV light, which causes it to fluoresce chalky white; this fluorescence is stronger under long-wave than short-wave UV.

This specimen was purchased at the 2016 Tucson shows from a dealer specializing in inclusion specimens. The cabochon, part a collection of otherwise natural items, was fully disclosed as a man-made novelty. Its appearance in the marketplace represents an emerging trend that gemologists and collectors will see with increasing regularity as the fascination with inclusions grows (see the author’s forthcoming article, “Evolution of the inclusion illusion,” in the Summer 2016 InColor). Careful inspection with a loupe or microscope will in most cases reveal the underlying nature of this inclusion.