Optimal processing conditions for fabrication of dense single-phase 6L-Ba 2 CoTeO 6 ceramics via the solidstate reaction method were determined. These ceramics possess a room-temperature crystal structure described by the centrosymmetric P3 ¯m1 space group. Polarized Raman spectroscopy enabled the observation of all the 25 predicted Raman modes and assignment of their symmetries. On cooling, BCTO ceramics exhibit two antiferromagnetic transitions at 3 K and 12.5 K, in broad agreement with a recent single-crystal study [P. Chanlert, N. Kurita, H. Tanaka, D. Goto, A. Matsuo and K. Kindo, Phys. Rev. B: Condens. Matter Mater. Phys., 2016, 93, 094420]. Low temperature Fourier-transform infrared reflectivity analyses suggest the antiferromagnetic phase transitions to be driven by small distortions of the CoO 6 octahedra, lowering locally their C 3v symmetry. This causes splitting of the associated vibrational modes, but without a long-range structural change. AC impedance spectroscopy revealed BCTO ceramics to be leaky insulators with an activation energy for conduction of ∼0.15−0.25 eV, which suggests electron hopping between mixed oxidation states of Co. † Electronic supplementary information (ESI) available: SEM of powder, processing conditions and densities, CIE LAB coordinates, EDAX, Rietveld refinement, AC impedance. See