Abstract Single crystals of Mn 3Ga 2Ge 3O 12 garnet, MGGG, have been obtained by chemical vapour transport using Cl 2 and CCl 4. Some structural investigations of Mn 3A 2Ge 3O 12 garnets, where A = Cr, Fe and Ga, have been performed. The lattice constant of MGGG is a 0 = 1.20166(2) nm. The distribution of elements is uniform and the stoichiometry is slightly changed between Mn and A elements only. In the garnets investigated the manganese is in a divalent state.