A marker alloy foreign implant made of a biodegradable metallic material and having the composition MgxYbyMz wherein x is equal to 10-60 atomic percent y is equal to 40-90 atomic percent z is equal to 0-10 atomic percent M is one or more element selected from the group consisting of Ag, Zn, Au, Ga, Pd, Pt, Al, Sn, Ca, Nd, Ba, Si, and Ge and wherein x, y, and z, together, and including contaminants caused by production, result in 100 atomic percent.
