Abstract: The present invention relates to a sterling silver alloy, copper-free in its basic embodiment, age-hardenable, with improved resistance to tarnishing, thanks to the presence of palladium in combination with zinc and indium, this alloy being mainly used for the realization of precious articles; the present invention also relates to a master alloy composition suitable for the production of said sterling silver alloy.

Abstract: The present invention relates to a sterling silver alloy, copper-free in its basic embodiment, age-hardenable, with improved resistance to tarnishing, thanks to the presence of palladium in combination with zinc and indium, this alloy being mainly used for the realization of precious articles; the present invention also relates to a master alloy composition suitable for the production of said sterling silver alloy.

Abstract: A master alloy composition for producing gold alloys with innovative refiners system comprising iridium (Ir): 0.01÷0.8% by weight, ruthenium (Ru): 0.002÷0.9% by weight, rhodium (Rh): 0.002÷0.8% by weight, and copper (Cu): 20÷99.965% by weight, wherein iridium (Ir), ruthenium (Ru) and rhodium (Rh) are the grain refiners.

Abstract: Gold alloy comprising, by weight, at least Gold Au≧33%, Iridium Ir≦0.4%, germanium Ge≦2%, 0.015% ≦silicon ≦0.3%, Phosphorus ≦0.02% and Copper Cu≦66%. The alloy can also comprise, in percentage by weight, Silver Ag≦34%, nickel Ni≦20% and Zinc Zn≦25%. In some variations the gold alloy can further comprise no more than 4% of at least one of the elements of the group constituted by cobalt, manganese, tin and indium, and no more than 0.15% of at least one of the deoxidizing elements of the group constituted by magnesium, silicon, boron and lithium. To the alloy can also be added at least one of the refining elements of the group constituted by ruthenium, rhenium and platinum in quantities not exceeding 0.4% by weight. The invention further relates to a master alloy for obtaining said gold alloy.