Tellurium mineralization in the northern Organ district, Dona Ana County, New Mexico
— Virgil W. Lueth

Telluride minerals in the northern Organ district occur in association with two distinct types of mineralization: (1) base metal sulfide mantos and (2) quartz vein and breccia bodies with gold, fluorite, sulfides, and tellurides. An east–west-trending fault served as the flowpath for mineralization with manto deposits localized by small anticlinal flexures in host Paleozoic sedimentary rocks. All manto deposits are confined to the dolomite units directly beneath the Percha Shale, a unit that acted as an impermeable barrier to ore fluids. Quartz vein and breccia deposits are present in the main fault, beneath the mantos, and in subsidiary crossfaults. Temperatures of mineralization, determined by homogenization temperatures of fluid inclusions (Th), overlap although mean temperatures in mantos (Th = 206°C) are higher than in the quartz-tellurium ores (Th = 178°C). Upper portions of the manta deposits are devoid of tellurides, while samples in close proximity to the quartz-tellurium ores contain the base metal tellurides, altaite (PbTe), and rickardite(Cu₇ Te₅) . The quartztellurium ores display a distinct paragenesis of galena-altaite-native tellurium, indicating increasing Te fugacity over time. Base metal telluride assemblages formed by reaction between preexisting sulfides and a tellurium- rich fluid.