Tetrahedrites are minerals which consist largely of earth-abundant and environmentally-friendly elements (copper and sulfur). This family of materials is attracting much interest due to their potential for thermoelectric energy recovery. Tetrahedrites are one of the best p-type thermoelectric materials known to date, due to their extremely low thermal conductivity. It has been recently discovered that the parent tetrahedrite, Cu12Sb4S13, exhibits a metal-semiconductor transition at 85 K, in which the electrical resistivity increases by two orders of magnitude. This transition is accompanied by a marked anomaly in the magnetic susceptibility and a structural transition which leads to a reduction in symmetry from cubic to tetragonal. We seek to collect diffraction data as a function of temperature to investigate magnetic ordering and determine the structure of this material below 85 K.