The recent expansion of zeolitic synthesis toward mixed geometry frameworks reflects their potential applications in shape-selective catalysis and absorption. Four scandium phosphates with three-dimensional frameworks have been hydrothermally synthesized. All structures were solved from single-crystal X-ray diffraction and were supported by 31P MAS NMR and infrared spectroscopy. Structure 1 ((C2N2H10) 8Sc8(ScO2)4(PO4) 4(HPO4)12·12H2O) consists of a novel framework with 14-membered rings (MRs) and 10-MR channels along the a and c axes, respectively. Ethylenediamine and water reside in the resulting supercage. Structure 2 ((C2N2H10) 2Sc4(HPO4)8) consists of a framework built from the corner-sharing of ScO6 octahedra with HPO4 tetrahedra whose connection results in a 8-MR channel down the a axis, where hydrolyzed cyclam resides. This compound is isostructural to a number of existing synthetic materials including a scandium phosphate, an indium phosphate, and an iron phosphate. Structure 3 (Sc4(HPO 4)8·4(H3O)) is a framework built in the same way as structure 2 but is described by a 12-MR channel down the a axis in which hydronium resides. This structure is isostructural to a ferric oxonium bis(hydrogenphosphate). Structure 4 (Sc4(PO4) 4·8H2O) is a framework built by the corner-sharing of PO4 tetrahedra with SCO4· 2H2O octahedra to form 8-MR channels down the a-axis. This structure occurs in nature as sterrettite, a scandium-bearing phosphate mineral, and has an isostructural indium phosphate. Crystal data: structure 1, P21/n, a = 8.603(2) Å, b = 15.476(3) Å, 16.504(4) Å, and β = 96.877(5)°, structure refinement converged at R = 0.0443; structure 2, P2/n, a = 9.4111(15) Å, b = 9.1066(15) Å, c = 9.6950(15) Å, and β = 117.272(3)°, structure refinement converged at R = 0.032; structure 3, P2/n, a = 5.3048(11) Å, b = 8.8230(18) Å, c = 14.779(3) Å, and β = 96.685(5)°, structure refinement converged at R = 0.0433; structure 4, P2(1)/n, a = 5.4429(8) Å, b = 10.2513(15) Å, c = 8.9094(11) Å, and β 90.253(7)°, structure refinement converged at R = 0.063.