Choudhary G. & Fernandes S. (2013) Inclusions in Indian Rubies. Presented at International Gemmological Conference (IGC) 2013 held in Vietnam from 12 -19 October 2013. Abstract in proceedings volume

An attempt was made to correlate the types of inclusions observed in rubies from various Indian states and their associated rock types. This study revealed a range of inclusions found in Indian rubies, which were of more or less similar type, pattern and appearance. No consistency was observed in the type and pattern of inclusion, restricted to a specific locality (states) and the associated rock types, although some of the minerals were identified only in specific locality such as hematite (in Chhattisgarh), chromite and green mica (in Orissa), and apatite and yellow spinel (in Tamil Nadu).

Choudhary G. (2013) Boron carbide imitation of black diamond. Gems & Gemology, Vol. 49, No. 3, pp 180-181

As black diamond has gained popularity in the past few years, so have aggregates of black synthetic moissanite and crystalline silicon. One specimen received by the Gem Testing Laboratory in Jaipur, a 1.04 ct black submetallic round brilliant, appeared to be synthetic black moissanite but proved to be boron carbide

Choudhary G. (2013) Corundum carving coated with a colored polymer. Gems & Gemology, Vol. 49, No. 3, pp 184-185

Coating, one of the traditional forms of enhancement, is still widely used on a number of gem materials. The latest is a dark violetish blue carving of the early Jain spiritual leader Lord Mahaveera, submitted as sapphire that turned out to be corundum coated with a blue colored polymer.

Choudhary G. (2013) Violet and Pink coated opals. The Australian Gemmologist, Vol. 25, No.2, pp 55-57

Two opal beads, one violet and one pink were studied, each turning out to be coated with coloured polymers. The presence of dye was detected by observing the microscopic features, absorption spectrum and reactions under ultra violet light, while detection of polymer was based on FTIR analysis. Raman spectra identified these opal beads as opal-C.