Choudhary G. (2009) Aventurine K-Feldspar, Midlands Focus, 14^th issue, pp 13 – 17

Recently, the Gem Testing Laboratory of Jaipur, India, encountered a few aventurine feldspars which proved to be potassium feldspar rather than the oligoclase variety (sunstone). The samples studied appeared to be sunstone feldspars as they readily displayed aventurescence, however, their physical, optical and chemical properties did not match those of sunstone but those of potassium feldspar. The overall features of these specimens were consistent with those of orthoclase feldspar.

Choudhary G. (2009) Tairus Created Gems: Part I – Beryl, Journal of Gems & Gemology, Issue 1, pp 28-30 (In Chinese with English abstract)

This study represents the gemmological properties of ‘Tairus’ created hydrothermal beryls, which were procured from the Tairus Co. Ltd. for educational and reference purposes. Their standard gemmological properties, such as RI and SG overlap with those of natural counterparts. Microscopic features, such as, ‘chevron’ growth can readily identify this material as synthetic which is visible even with unaided eyes, however, there might be cases when the internal features may not identify the material; in such cases, FTIR and EDXRF analysis may be needed to conclude the stones as synthetic

Choudhary G. (2009) Various Remarkable stones tested at Gem Testing Laboratory, Jaipur, India. Presented at the GIT 2^nd International Gem and Jewelry Conference held in Bangkok, Thailand, March 9-12, 2009. Abstract in proceedings volume.

At the Gem Testing Laboratory of Jaipur, we receive for identification various types of gem materials ranging from natural, synthetics, imitations and treated counterparts. Few selected cases were presented, which included, "A remarkable tourmaline crystal", "Natural gems with Nail-head spicules", "Synthetic emerald necklace", "Synthetic emerald with natural like abundant liquid fingerprints", "Synthetic multicoloured quartz", "Synthetic star sapphire with hexagonal zones", "A YAG with reverse colou-change", "Banana and Turtle inclusions in spinel" and "Fusion Composites".

Choudhary G. & Golecha C. (2008) Note from the laboratory – Anglesite, an unusual collector’s gemstone, Australian Gemmologist, 23, 314-315

An unidentified light gray and transparent crystal weighing 29 carats was submitted for examination at the Jaipur India, Gem Testing Laboratory. It was remarkably dense and a hydrostatic Specific Gravity determination gave a value of 6.36, consistent with either anglesite, i.e. lead sulphate, (6.3-6.4, usually 6.38) or cerussite, lead carbonate (6.4-6.6, usually 6.55). Use of simple acid test and specific gravity helped to identify the mineral as anglesite. Some tiny green coloured hexagonal crystals were also attached to this anglesite crystal. Morphology, cleavages and typical green colour were consistent with that for Dioptase.