Ruthenium is a chemical element that has the symbol Ru and the atomic number 44. A rare transition metal of the platinium group of the periodic table, ruthenium is found associated with platinum ores and used as a catalyst in some platinum alloys. Due to its ability to harden platinum and palladium, ruthenium is used in platinum and palladium alloys to make wear-resistant electrical contracts. It is sometimes alloyed with gold in jewelry. The addition of 0.1% ruthenium to titanium improves its corrosion resistance a hundredfold. Ruthenium is also used in some advanced high-temperature single-crystal superalloys, with applications including the turbine blades in jet engines. It is also a versatile catalyst for use in oil refineries and other industrial processes.