A sample of calcium metal is contaminated by a certain amount of highly toxic, radioactive thorium metal (Th). A 10.00-gram sample of this mixture is dissolved in acid, and reacted with excess sodium oxalate to form a precipitate which is a mixture of calcium oxalate, CaC2O4, and thorium oxalate, Th(C2O4)2. The total mass of this precipitate is 31.03 grams. Determine the mass of each metal in the original 10.00-gram mixture.