Choudhary G. (2010) A new type of composite turquoise, Gems & Gemology, Vol. 46, No.2, pp 106-113

Several conspicuously coloured specimens marketed as dyed and/or stabilized turquoise were recently examined. They were purple to purple-pink, yellow-green, and blue, in veined and unveined varieties. Testing revealed that all the specimens were composites of turquoise pieces bonded together; the purple to purple-pink and yellow-green samples were bonded with a coloured polymer, and the blue ones had a colourless polymer. This article presents the gemological properties and EDXRF and FTIR analyses of this material, along with its reaction to the solvents acetone and methylene chloride

Choudhary G. (2010) A chatoyant malachite, Australian Gemmologist, Vol. 24, No.2, pp 44-45

The Gem Testing Laboratory of Jaipur, India encountered an interesting specimen of deep green malachite weighing 9.57 carats, which displayed a broad chatoyant band. This report describes this unusual and interesting specimen of chatoyant malachite. This cabochon was not distinctly colour banded; magnification revealed a fibrous structure oriented perpendicular to the direction of the subtle banding. This structure was apparently responsible for the chatoyancy of the stone.

Choudhary G. (2010) New inclusions with crystal glass, Journal of Gems & Gemology, Issue 2, pp 43-45 (In Chinese with English abstract)

Glass is the most common and widely used imitation stones, which can imitate almost any colour, transparent and one opaque gem materials. Typically, only glass imitation emerald, ruby, sapphire, diamond, tourmaline and aquamarine stones and a few other materials. Although widely used glass, but with a few synthetic gem compared to the identification of non-challenging. Most of the glass through its typical characteristics of inclusions can be identified, such as various shapes of bubbles, swirl patterns or devitrification effects.

Choudhary G. (2010) A different kind of composite, Gems & Jewellery, Vol. 19, No.1, pp 12-14

Gagan Choudhary reports on two green coloured stones which were submitted to the Gem Testing Laboratory of Jaipur as emeralds, but were identified as composites of an unusual composition. The specimens consisted pale coloured to colourless beryl at centre surrounded by small pieces of green glass on the pavilion. The central piece contained tubes, crystals, blades, etc typically associated with a natural beryl or emerald. Therefore, if not observed properly, these composites can easily be misidentified as natural emeralds