Clay deposits in playa lake/salar environments are now recognized as a significant deposit type for economic concentrations of lithium. Clayton Valley, Nevada, the location of North America’s only lithium brine producer, also has paleo-lacustrine lithium clay deposits of significance, including the Zeus property lithium clay deposit in the eastern part of the valley. This study presents new mineralogical studies on the Zeus property lithium clays to help understand their genesis and the potential economic extraction. The Zeus property (owned by Noram Ventures Ltd.) currently has an inferred resource of 17 million tonnes @ 1060 ppm Li (96,500 tonnes Li2CO3 equivalent). Initial XRD and glycolation techniques for two Zeus property bulk samples, one from the surface (relatively oxidized) and the other from ~35 m depth (relatively reduced) indicate that the clay fraction (~50%) includes smectite, illite/muscovite, chlorite, and a significant amount of amorphous matter believed to be poorly crystalline smectite + illite. The non - clay fraction has calcite, quartz and sanidine. Hectorite, sulfates, borates and halides have not been detected (yet). TIMA (Tescan Integrated Mineral Analyzer, using SEM backscatter and X-ray imaging), and petrography will help determine the mode and mineral chemical compositions in more detail, as well as addressing the relative abundance of authigenic vs. transported clay material. Initial indications are that the smectite and illite are authigenic, and formed in and below a playa lake with evolving lithium (and other cation) concentrations. The lithium budget is likely controlled by smectite and illite. Lithium adsorption onto illite and smectite surfaces and crystal edges is dependent on lithium concentration in brine solutions. Smectite adsorbs significantly higher lithium concentrations and has a higher cation exchange capacity than illite. The apparent absence of hectorite may indicate that smectite and illite formed at low temperatures, away from the influence of hydrothermal fluids and hot springs, which are present on the western side of Clayton Valley. Hectorite is relatively refractory and hinders lithium extraction in weak acid solutions. Leaching tests are underway to determine the most effective methods to extract lithium from the clays, and membrane filtration/ion filtration techniques will be tested for lithium solute concentration and purification.