Thermoelectric materials based on tetrahedrite structure for thermoelectric devices iNTRODUCTION Growing concern with energy independence and sustainability has initiated research into methods that can help to increase energy efficiency. One method thermoelectric devices converts waste heat from current processes into energy. These devices take advantage of a temperature gradient across the device creating a voltage from the temperature difference. The materials that produce thermoelectric devices with the highest figure of merit or ability to produce thermoelectric power require rare or toxic materials (e.g. Te Ag Co Pb). This prevents thermoelectric from being used in large-scale applications. If thermoelectrics are to be used in larger settings new materials are needed that are inexpensive safe and are composed of earth-abundant metals. Description of Technology This technology is a set of compounds based upon natural tetrahedrite structures that can be used for thermoelectric devices. Tetrahedrite is a copper antimony sulfosalt that is globally available and in abundance near hydrothermally active sites. The tetrahedrite is milled and doped to create desired thermoelectric properties most importantly a high figure of merit.