Tetrahedrite offers advantages over other state-of-the-art thermoelectrics, such as lead telluride, because of its low cost and environmentally friendly composition. However, typical sealed-tube synthesis of tetrahedrite can require multiple days or weeks. In this study, tetrahedrite was synthesized by two different processes, mechanical alloying and reactive spark plasma sintering (SPS), that require significantly less time than the conventional furnace-ampoule method. Thermoelectric properties were measured for samples of Cu10Ni2-xZnxSb4S13 (x=0, 0.5, 1, 1.5, 2) synthesized using both techniques. Peak dimensionless figure of merit (ZT) values were obtained for Cu10Ni2Sb4S13 with ZT=0.64 and ZT=0.62 at 623 K in mechanically alloyed and SPS reacted samples, respectively.