Report Verification

Search

Publications

Being based in a gem centre like Jaipur, GTL is exposed to a range of unusual and bizarre gem materials submitted for identification. Because of the dedication and passion our staff gemmologists possess, these gem materials undergo a thorough research for their complete understanding. The results of such research are shared with the world through publications in various highly read gemmological journals of international repute.

In The Press


Read More...

Choudhary G. (2014) Aquamarine with Unusually strong Pleochroism. Gems & Gemology, Vol. 50, No. 3, pp 244-245

A transparent grayish blue aquamarine was submitted which was interesting for its strikingly strong pleochroism. It displayed deep saturated blue along the e-ray (left), similar to sapphires, and a pale bluish green along the o-ray (right). Absorption spectra confirmed the sample to be an aquamarine rather than a Maxixe-type beryl.


Download PDF

Choudhary G. (2014) Emeralds Partially Coated with Amorphous Carbon. The Journal of Gemmology, Vol. 34, No. 3, pp 242-246

Nine faceted emeralds submitted to the Gem Testing Laboratory, Jaipur, India, were identified as coated owing to the metallic to sub-metallic reflections on their pavilion facets. The coated surfaces did not show any diagnostic features with routine EDXRF and Raman spectroscopy. However, some samples had concentrations of the coating substance in surface cavities, and Raman analysis of those areas revealed the presence of amorphous carbon. Specifically, the presence of a broad absorption feature at ~1550 cm-1 with a shoulder at ~1360 cm-1 identified the coating substance as an ‘a-C’ type film. Microscopic observation showed that the coating was damaged and removed from several areas, suggesting its instability to normal wear and tear.


Download PDF

Choudhary G. (2014) Synthetic Ruby Doublet with a Natural-appearing Sheen. The Journal of Gemmology, Vol. 34, No. 2, pp 110-111

Upon initial observation of a purplish red specimen with the unaided eye under normal room lighting, it displayed sheen-like reflections when viewed face-up. This sheen was caused by a plane consisting of fine reflective dendritic inclusions positioned just below the girdle. This confirmed the specimen was a doublet and the components used were synthetic rubies on both crown and pavilion sides.


Download PDF

Choudhary G. (2014) Dyed Bone as a Red Coral Imitation. Gems & Gemology, Vol. 50, No. 2, pp 164-166

An orange-red cabochon measuring that was presented as red coral proved to be dyed bone. The sample lacked the typical “tree ring” or “striated growth” structure seen in corals, though it did display a network of fine veins throughout. When viewed from above, these veins appeared subparallel and oriented along the length of the cabochon. They also displayed orange-red color concentrations against the cabochon’s whitish bodycolour, suggesting that the material was both dyed and organic. Chemical, gemological, and observational features indicated bone, which was further confirmed by Raman spectroscopy.


Download PDF

Powered by Gati Technlogies