Summer 2010

Featured Gem News International: Tsavorite and Other Green Garnets Reportedly from Afghanistan

In December 2008, Farooq Hashmi (Intimate Gems, Jamaica, New York) loaned GIA some green gem material that was sold to him as garnet in Peshawar, Pakistan. He purchased it several years ago, and was told it came from Kala, Kunar Province, Afghanistan. He reported seeing several parcels over the years in Peshawar, although the pieces tended to be small, mostly suitable for cutting melee stones.

Examination of the 18 rough samples (0.08–0.21 g) and three faceted stones (0.09–0.20 ct) revealed the following properties: color—medium-light to medium-dark yellowish green to green; RI—1.74 to 1.77 (spot readings of the rough samples fell within this range); hydrostatic SG—3.43–3.64; fluorescence—inert to long-wave UV radiation, and inert to very weak orange to short-wave UV; and absorption bands or cutoffs at 440 nm visible with the desk-model spectroscope. These properties are consistent with those reported for grossular to grossular-andradite garnet, although some of the SG values are somewhat low (as compared to the 3.57–3.66 range reported by C. M. Stockton and D. V. Manson, “A proposed new classification of gem-quality garnets,” Winter 1985 G&G, pp. 205–218). EDXRF spectroscopy of all the samples revealed major amounts of Ca, Al, and Si, with minor Mn, Fe, Ti, Cr, Cu, and Zn. Microscopic examination revealed needles, liquid inclusions, partially healed “fingerprints,” dark crystal inclusions, and iron staining.

Some of these samples of grossular to grossular-andradite were green enough to be considered tsavorite. We are unaware of tsavorite from Afghanistan being previously produced.

Erica Emerson and Jason Darley