US Patent 7128792 Sterling silver manganese alloy compositions

A unique manganese silver alloy composition is provided, which alloy exhibits the long desired properties of exceptional as-cast hardness and reversible heat treatability, in addition to offering reduced fire scale, reduced voids and porosity, reduced grain size, and reduced oxide formation when heated consisting essentially of the following parts by weight: about 92.5–92.8% silver, about 2.0–3.0% copper, about 2.0–3.0% zinc, about 0.03–0.05% indium, about 0.01–0.03% tin, about 0.20–0.50% boron/copper alloy (22% boron, 98.0% copper) about 0.50–0.90% silicon/copper alloy (10.0% silicon, 90.0% copper), and 0.01%–0.10% manganese “30” (0.30% of a manganese-copper alloy containing about 30% manganese and about 70% copper).