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This paper was presented at the 2006
Typically, silver for use in jewellery is refined to 99.9% purity. This is pure enough for creating standard sterling silver, which only has 7.5% copper added to it to attain the working qualities silversmiths and jewellers have become used to over several hundred years. Although the working qualities of traditional sterling silver are wonderful, the major drawback is firescale/stain that is commonly formed when soldering or casting. To overcome this problem, anti firescale sterling silver alloys have been developed over the last 10 years. These alloys are more complex, making it essential to know the quality of all alloying components as well as the major metal being alloyed. In working to improve the casting quality of our firescale-free silver alloys, some trace elements still present in the refined silver were discovered to be causing problems. This study discusses the presence of very small quantities of some trace elements—in particular tellurium, selenium, bismuth and antimony—which, although present in only a few parts per million, can represent a threat to the production of quality, stable, silver casting. Mr. Eccles is Managing Director of the custom casting company he founded in 1964. He designed several novel precious metal alloys that are in use worldwide. At previous Santa Fe Symposia® he has presented papers on alloying precious metals and has been awarded both the Industry Leader and Ambassador awards. In 2003, he was appointed Officer of the Order of Australia (AO) for service to the jewellery craft and to the technical education through the promotion of trainee-ship programs in Australia and overseas. This is his fourth presentation for the Symposium. |
