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Bright Sterling Silver; For many years people have been striving to produce a fire-stain free silver, but it is only in the last 5-6 years that a breakthrough has been made with a real improvement to the qualities of standard sterling silver. Until recently there was only one standard alloy of sterling silver in major use, being 92.5% silver and 7.5% copper, the qualities and characteristics of which are well known. A beautiful, white, lustrous, decorative metal, easy to fabricate and cast, but difficult to work without developing fire-scale, using normal soldering and annealing techniques. When polished, it in time develops a nasty shade of black if not paid sufficient attention. Now we have formulations that improve the hardness and minimise finishing time by virtue of the anti fire-scale properties and with improved tarnish resistance. Due to complaints of fire-scale in sterling silver in the early 80's I tried an alloy containing silicon and zinc but found it too soft and didn't continue with it. A little later whilst attending a Santa Fe Symposium I was offered a formula for a fire-scale free, sterling silver. It certainly proved to be fire-stain free, but for most practical jewellery purposes, it too was soft, and did not harden appreciably.
The challenge was to give it some degree of hardness to make it a more useful alloy. So with the judicious use of Germanium, I began a series of test alloys to increase the hardness. Within a very short time I had proved the hardness could be increased. To achieve the optimum alloy with improved characteristics, yet retaining similar working properties as standard sterling silver, has been an ongoing search with improvements occurring at regular intervals over the past 5 years. The original master alloy contained seven elements and to balance all of these to obtain the qualities required for a particular purpose entailed a lot of trial and error formulating. As even less than 0. 1 % of any given constituent could change the result. By the addition of a careful formulation of mainly germanium, zinc, silicon and trace elements we have been able to develop a range of sterling silver alloys. The broad range of parameters within our patent specifications allows for silver alloys from 830/1000 through 925/1000 (sterling silver), to 950/1000. The scope is there to create an alloy for a particular purpose i.e. one that will work harden quickly or slowly or will cast a little harder than standard sterling, with the attributes of being fire-stain free and with increased tarnish resistance. |
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