The gemological identification of emeralds and blue sapphires.

The gemological properties that allow natural emeralds and blue sapphires to be distinguished from other gemstones are summarized int this paper. A variety of synthetic and laboratory-treated emeralds and blue sapphires are also encountered in the jewelry industry today. Gemologists distinguish these latter materials from their natural counterparts based primarily upon features seen with magnification, such as inclusions and/or growth zoning. In some cases, however, these observations and standard gem-testing methods are insufficient, and the use of non-destructive analytical methods, such as optical spectroscopy and chemical analysis, are required for positive identification. The commercial value of synthetic and treated gems are much less, and can be insignificant in comparison to that of an important untreated natural gemstone. Identification of synthetic and treated gem material is essential to maintaining integrity in the jewelry industry. Loss of consumer confidence in the gemstones sold at the jewelry counter could have a negative impact on the exploration and mining of natural emerald an
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Summary: The recovery of cyanide from a gold mill solution containing high levels of copper (400 mg/L to 900 mg/L) using the AVR process was evaluated. It was determined that acidification to pH 2 to 3 provides a suitable balance between HCN generation, copper precipitation and acid consumption. A short pilot plant campaign showed that ~75% of the feed WAD cyanide was recovered while the remainder precipitated along with copper upon acidification. The acid consumption averaged 3.5 g H2SO4 per litre of...
Publication: CIM Bulletin
Author(s): P.A. Riveros, D. Koren, V.M. McNamara, J. Binvignat
Issue: 1025
Volume: 91
Year: 1998
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Summary: LÕanalyse des sŽquences dÕexploitation, actuellement en usage pour les gisements tr?s inclinŽs, a dŽmontrŽ quÕelles ne sont pas toujours optimales du point de vue du contr™le des terrains et de la concentration des travaux dÕabattage (nombre de chantiers simultanŽment en opŽration). Effectivement plusieurs sŽquences sont tr?s propices ˆ la crŽation des nombreuses zones de hautes contraintes, qui sont ˆ lÕorigine des effets de pilier. LÕŽtude de cas de la mine Lac Shortt a dŽmontrŽ que...
Publication: CIM Bulletin
Author(s): S. Planeta, J. Szymanski, A. Coulombe
Issue: 1025
Volume: 91
Year: 1998
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Summary: In this paper, the author offers a personal view of what the next 30 years holds for mineral processing. Restating that mineral processing will remain a vibrant industry in raw material production, growth opportunities in waste management are identified. The processing sequence familiar now (mining ® mineral processing ® extraction) will become more interwoven. In situ processing (i.e., milling underground) will evolve from concept to demonstration. Opportunities to exploit physical propertie...
Publication: CIM Bulletin
Author(s): J.A. Finch
Issue: 1025
Volume: 91
Year: 1998
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