Tooeleite is a ferric arsenite sulfate mineral only found in acid mine drainage at present, and its chemical formula is Fe₆(AsO₃)₄(SO₄)(OH)₄·4 H₂O. Few literatures have reported this mineral, and hence some important spectroscopic and mineralogical data are lacking. The authors synthesized tooeleite using temperature-constant water batch reactor, and for the first time adopted infrared and Raman spectroscopy techniques to characterize it. The result show that: the characteristic peak at FTIR of 770 cm^-1 is attributed to stretch vibration of As—O; the characteristic peaks at Raman of 663, 609, 512, 455 and 365 cm^-1 are attributed to the stretch vibration of As—OH (υ₃), asymmetric stretch vibration (υ₅), asymmetric bending vibration (υ₄) of AsO₃^3- and bending vibration of O—As—O; the incongruent dissolution occurs when pH of solution is higher than 3. The batch experiment determined for the first time the solubility product (K_sp) and the standard Gibbs free energy of the reaction, which are 10^7.7 and -3 605 kJ/mol, respectively.