We report here the facile synthesis and structural characterization of gamma-Ca(PO3)2, a novel polymorph of calcium polyphosphate. The single-step synthesis of this potential biomaterial was achieved using flux methods at 250 degrees C, yielding a single-phase product stable at room temperature. Single-crystal X-ray diffraction determined the structure to be of monoclinic symmetry (a = 9.5669(2) angstrom, b = 9.5023(2) angstrom, c = 10.3717(3) angstrom, and beta = 93.474(2)degrees, space group Cc), with layers of helical polyphosphate chains directed alternately along the  and  unit cell directions to produce a unique arrangement of criss-cross polyphosphate layers separated by calcium ions. Further structural characterization by MAS-NMR and FT-IR was found to be consistent with this structure. Thermal studies indicated that gamma-Ca(PO3)(2) is stable up to 690 degrees C, whereupon it irreversibly converts to the P-Ca(PO3)(2) polymorph.