Whilst doing a survey of Lithium mining in North America, I blundered into a small cinder cone. It is found in the Clayton Valley of western Nevada south and west of Tonopah.

A link from the University of Nevada, Reno, gives some details on this cone as well as some interesting photographs.

Just to the south of this cinder cone is the Chemetall Foote Corporation Silver Peak brine facility. Lithium rich brines are pumped into evaporation ponds for concentration of the lithium salts. US 7390466 says that the Silver Peak brines contain 0.02 wt % Li.  The richest Li brine can be found in the Salar de Atacama brines in Chile. The Atacama brines contain from 0.15 to 0.193 wt % Li.