Hi Richard and Kenneth,
I also have cast with the silver of which Kenneth speaks. I
believe some (or all) of the copper content is substituted with
silicon. It cast and cleaned up as well as regular sterling
casting grain… but didn’t come out of the investment dark. My
only question was whether it would antique with liver of sulfur
since it lacks the copper content. I am happy to report it does
give a nice contrast, and doesn’t seem to require repolishing,
over time, like normal sterling. It fusion welds, as well! I
got my casting grain from Rio Grande in Albuquerque… although
I’m sure there are other sources (as Kenneth mentioned).
Dave Sebaste
Sebaste Studio
Charlotte, NC