Gem News International Gems & Gemology, Fall 1991, Volume 27, No. 3

Fall 1991 Gem News International

            Argyle Set to Expand with Mining at Home
            Argyle Also Plans to Expand Cutting in China
            Operations Re-Established at Elizabeth Bay
            Warnings of Large-Scale Theft
            New Soviet Diamond Source
            Additional Diamonds Recovered at Fort a La Corne, Saskatchewan, Canada
            Conference on Synthetic Diamond and Diamond-Like Coatings
            New Diamond Cuts
            Historical Diamond Photographs
Colored Stones
            Colombia Reports Record Emerald Exports
            Large South Sea Pearl
            Myanmar to Authorize Thai Buyers
            Postage Stamp Commemorates Large Burmese Ruby
            Small-Scale Sapphire Mining Continues in Thailand
            Tanzanian Spinel
            Update from Tanzania
            Tanzania Invites Tenders for Mineral Rights
            Large Paraiba Tourmalines
            Tourmaline with Unusual "Color Change."
            Tourmaline/Andalusite: A Pleochroism Caveat
            Purple and "Chrome" Green Vesuvianites from Quebec
            Unusual Red Zoisite
            Faceted Gems Coated with Diamond-Like Carbon
            Montana Sapphire Heat Treatment
            More Experimentation with Blue Diffusion-Treated Sapphires
            Red Stones Also Experimented With
Synthetics and Simulants
            Porous Gilson Synthetic Opal
Instrumentation and New Techniques
            Distinguishing Diffusion Treatment from Surface Coating
            New Setting Method Challenges Diamond Testers
            Jewelry Imaging/Teleconferencing System Introduced
            Tweezer Improvement
            Tucson Gem and Mineral Show 1992
            American Craft Assn. Supports Legislation
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