Whats the deal with sterling silver and copper turning black?
That is firescale and it’s copper to blame. That black coating is basically a result of heating copper in the presence of oxygen, and can be removed in a “pickle” solution, or manually by filing and sanding. The lower firing temperatures possible with Low Fire Art Clay Silver reduces firescale and allow for a better joint between the sterling and Art Clay. We do not recommend firing sterling at higher temperatures, like 1472°F, or torch firing, because the firescale may prevent a good bond with sterling, which may cause problems. Depending on handling, sterling may become significantly weaker when fired.