Unless expressly stated otherwise in the report, GFCO GEM LAB restricts it testing to standard gemological equipment to identify gemstones, detect treatment and give countries of origin. Gemstones are checked using:
In the specific case of Paraiba Tourmalines, to be be called "Paraiba", the standard/"rule" is a tourmaline should have a fair color tone and high saturation or good brilliancy with color varying between blue and green but also contain some degree of copper and manganese. The two methods to detect copper and manganese are EDXRF and LA-ICP-MS. EDXRF is a semi-quantitative method of analysis with the advantage to be fast and relatively cheap but with the disadvantage that the amount of copper is not quantified in a precise manner. In contrast, LA-ICP-MS is a quantitative method but is slightly destructive as the gem is to be hit by a laser in order generate a small cloud of particles to be analyzed by the spectrometer. LA-ICP-MS is more costly and in some cases the damage to the gem is visible. GFCO has different policies regarding the appliance of the term "Paraiba":
For the Tourmalines with a color deserving the "Paraiba" name but not tested for chemical composition, the term "Paraiba" is mentionned in the color area and the trade name as blue/green tourmalines with a special comment on the left page of the report saying "Not EDXRF tested for presence of copper".
For the tourmalines tested with EDXRF meeting the color requirement and where the presence of copper is confirmed, reports are issued with trade name as "Paraiba Tourmaine" with a special comment on the left page of the report saying "EDXRF testing has confirmed the presence of copper"; nonetheless, the method of testing being semi-quantitative, the exact amount of copper is not determined and thus cannot be guaranteed to always be considered sufficient if tested with LA-ICP-MS method.
In some cases, sapphires, yellow and orange sapphires heat treated with the adding of the gaz Beryllium can be identified as Be treated by observing the inclusions and/or color zoning. Similarly, in some cases heat treatment with Be can be excluded with the same observation. In the cases which are unclear, GFCO GEM LAB mentions "HEAT" with a special comment on the left page of the report "Not LIBS tested for light element heat". For the stone which the gemologist excludes heat treatment with beryllium, the term used is "STANDARD HEAT". In some cases. yellow sapphires can be irradiated and the color fade, GFCO does not currently test yellow sapphires for irradiation.
GFCO GEM LAB does not specify the type of filler used for clarity enhancement of emeralds but quantified the degree of clarity enhancement based on the presence of a filler and the amount of fissures/cracks present in the gem. Identification of the filler requires FTIR testing.
Although no advanced equipment is used, standard testing remains decisive in most cases outside the cases which simply cannot be tested without recourse to advanced equipment (which GFCO does not test or discloses the limitations on the report). As acknowledged by even the most prestigious gemological laboratories, the most important tool in gemology remains the microscope where the eyes & memory of the gemologist lead to the conclusion; thus, laboratories equipped with standard equipment only are also able to offer high quality testing as we work to do.