Spring 2011

Trapiche Emerald Imitation

Two interesting samples resembling trapiche emerald were recently brought to our attention by gem dealer Farooq Hashmi (Intimate Gems, Jamaica, New York). They had been cut from the same “crystal,” which closely resembled a natural trapiche emerald. The “crystal” was obtained on a mid-2010 trip to Colombia from a seller who was not initially aware he had acquired an imitation. To better expose the assembled nature of the item, Mr. Hashmi had it sliced and polished into the pieces shown in the figure.

The samples weighed 5.17 and 3.53 ct, and measured ~10–11 mm in diameter. Magnification revealed an unevenly distributed dark substance on the original surface of the rough. The pieces of the assemblage were joined with adhesive that was colorless in some areas and black in others, to better mimic natural trapiche structure. Raman spectroscopy identified the assembled pieces as beryl and the substance holding them together as a polymer. Raman analysis of inclusions in the beryl confirmed the presence of dolomite, calcite, and pyrite. A cylindrical core of slightly darker green beryl was located in the center of the assemblage. The continuity of the inclusions throughout the assembled pieces (except in the core) suggests that the original crystal had been drilled through the middle and then cut into six equal sections.

A cabochon cut from a similar “trapiche” assemblage was reported in the Fall 1998 Lab Notes (p. 212). It consisted of a clear core surrounded by a black rim from which black arms extended in six directions (for comparison, see E. J. Gübelin and J. I. Koivula, Photoatlas of Inclusions in Gemstones, ABC Edition, Zurich, 1986, p. 253). The pres­ent example shows that such assemblages continue to be found in the marketplace, even mimicking rough material.

Riccardo Befi (rbefi@gia.edu)
GIA Laboratory, New York