An uncommon yet highly symmetric crystal form of a Mn-based heteropolytungstate (Mn-HPT), Mn 7 (MnW 12 O 42 (OH) 4 )• 8H 2 O, has been synthesized by a unique solvothermal method at 180 °C for 6 h. The nature of the solvent (water/ethanol = 50/50 by volume) and the presence of citric acid were the key reasons for the formation of the Mn-HPT phase and its hollow spherical morphology under the said experimental conditions. Combined powder X-ray diffraction analysis and field emission scanning electron miroscopy (FESEM) analysis reveals that the structure (cubic, space group Im3) consisted of [MnW 12 O 42 ] 10− polyanion with Mn in a central 12coordinated cavity, which cross-linked three dimensionally with other MnO 6 octahedra, to form the characteristic rhombododecahedron shaped particles of size ∼150 nm. Each polyanion was made of six pair of face shared WO 6 dimers (W 2 O 9 ) with mean W•••W separation of 2.98 Å. The WO 6 octahedrons were tilted to an O−W−O angle of 99.1°with four different types of W−O bonds. The structure was further characterized by thermogravimetric (TG), infrared (IR), Raman, and X-ray photoelectron spectroscopy (XPS) study. UV−vis diffuse reflectance spectroscopy (DRS) analysis suggests that the material essentially was an indirect band gap semiconductor with E g = 2.33 and 2.93 eV corresponding to the transitions from two different sets of nonbonding HOMO (O 2p) to the π* LUMO (W 5d). Room temperature photoluminescence (PL) analysis further delineates the HOMO−LUMO transition in the blue (412 nm) to green (525 nm) region with characteristic mean decay lifetime ∼8 ns.