Abstract: A novel alloy contains Pt as a principal component and also contains 0.1 to 15% Ru and 0.1 to 15% Ir in weight rate in Pt to overcome a problem in that Vickers hardness (Hv) of the conventional Pt-based alloys do not correspond to requirements in diversified ornaments because of their respective Vickers hardness (Hv): Hv 125 to 135 for Pt—Pu-based alloys and Hv 80 to 100 for Pt—Ir-based alloys.

Abstract: A gallium alloy for dental restorations which is hardenable at mouth temperature or around 37.degree. C. or more after triturating multicomponent liquid gallium alloy with alloy powder, is disclosed. The mixture has a heterogeneous structure after hardening, and contains as the overall composition, 9-47% gallium, 1-35% indium, 0.2-38% tin and 1-68% silver as indispensable components and one or more elements selected from 0.4-35% palladium, 0.5-25% copper and 0.4-12% zinc as arbitrary components. The multicomponent liquid gallium alloy contains 45-85% gallium, 5-40% indium and 1-30% tin as fundamental components and small amounts one or more elements selected from silver, palladium, gold, platinium, copper, zinc and germanium as arbitrary components. The alloy powder contains 1-85% silver and two or more elements selected from 1-40% tin, 1-40% palladium, 1-30% copper, 1-15% zinc and 1-25% indium.