"As used herein, calcium/oxyanion-containing particles include calcium phosphate minerals, apatites, and apatite precursors of the general formula Can Mm Xr Ys, where M is a paramagnetic metal ion, radiopaque metal ion, radioactive metal ion, or stoichiometric mixture of metal ions, X is a simple anion, Y is an oxyanion including tetrahedral oxyanions, protonated or unprotonated, carbonate, or mixt" . . . .