gems, spinel, star spinel, Sri Lanka

Recent developments in Sri Lankan gemstone production are summarised from information supplied by dealer Gordon Bleck, with particular attention to unusual materials and newly reported occurrences. Mining was reportedly being hindered by terrorist activity, especially in remote jungle areas around Okampitiya, while Ratnapura remained relatively safe. Rubies from a newly reported locality near Hambantota were described as unusually good in quality and deeper in colour than material generally associated with Sri Lanka, although individual stones rarely reached one carat. Deep pink fancy sapphires had also been found in the Matara district on the southern coast, but production was limited and fashioned stones seldom exceeded two carats. A notable departure from previously encountered Sri Lankan star spinel was the discovery in the Ratnapura district during 1991 of saturated red material with a high degree of transparency. Earlier examples familiar to the editors had generally been almost opaque, very dark, and weakly saturated purple. A photographed 1.12-carat red star spinel illustrates the distinctive combination of colour, transparency, and asterism. Other reported finds included clean, light yellow danburite from the Nirialla River, approximately ten kilometres from Ratnapura near Palawela and Nirialla. A large river-bed specimen yielded an 11.52-carat pear-shaped gem, while smaller fragments came from the river bank; this newer production was less included than earlier material. Two translucent yellowish green andradite crystals were among the year’s rarities, the larger measuring about two centimetres across and showing combined dodecahedral and trapezohedral forms. Increased quantities of colour-change spinel, sapphire, and garnet were also reported. Facetable kornerupine had become more available, including a 17.01-carat brownish green stone from central Sri Lanka whose unusually light tone was noteworthy for its size, whereas cat’s-eye kornerupine had become scarce. An unusually large, 5.00-carat blue sillimanite from Ambalapitiya completed the selection. The report documents the diversity of the country’s gem output through specific examples, emphasising differences in colour, transparency, size, inclusion abundance, and availability.