Helical Inclusion in Colombian Emerald
GIA’s Tokyo laboratory recently examined a 7.54 ct natural emerald containing a 3D helical inclusion (see above) resembling a DNA double helix or fish bone. This helix, consisting of whitish grains, reached the emerald’s surface. The other associated inclusions were jagged three-phase fingerprints, growth tubes, and the gota de aceite optical effect (R. Ringsrud, “Gota de aceite: Nomenclature for the finest Colombian emeralds,” Fall 2008 G&G, pp. 242–245). All these features supported a Colombian origin. To date, three emeralds examined in GIA’s Tokyo laboratory that were reportedly Colombian have exhibited similar inclusions. This helical inclusion may therefore be a characteristic of Colombian emeralds. Such a discovery within a stone is always pleasing.
