The phosphorus-rich variety of ellenbergerite (Mg_0.61Ti_0.08□_0.31)₂(Mg_0.52Al_0.43□_0.05)₁₂[SiO₃(O_0.29(OH)_0.71)]₆[(P_0.71Si_0.20□_0.09)O₃OH]₂(OH)₆ was studied by X-ray diffraction and IR spectroscopy. The structure was refined in sp. gr. P6₃ mc to R = 0.0248. The structure of phosphorus-rich ellenbergerite retains the octahedral framework observed in the structures of ellenbergerite, phosphoellenbergerite, ekatite, and a series of structurally related synthetic compounds. The structure of phosphorus-rich ellenbergerite differs from the structure of ellenbergerite primarily in that the Mg and Al cations in the phosphorus-rich variety are disordered in the octahedra of the framework, thereby leading to higher symmetry, and the channels of triangular cross section are occupied predominantly by P tetrahedra.