Gabbs Mine

Gabbs, Nye County, Nevada, USA. A magnesium/magnesia (MgO) mine that was active from WW II until just recently. It was originally the subject of an intense development effort around the beginning of WW II, because magnesium was a critical component of high-performance aircraft alloys, and it was feared that the Axis powers were way ahead in that respect. (A magnesium gap!) The raw ore was shipped to the newly opened plant in Henderson, Nevada, just outside Las Vegas, for processing into Mg metal. Lots of hydropower was available from the newly finished Hoover Dam, and the electrolytic process for magnesium separation requires lots of electricity. It's analogous to aluminum in that respect. The shipping route was very circuitous; there was no direct rail link, so the ore was trucked to Luning, NV (at that time a railhead--the tracks have since been torn up), shipped north to the transcontinental raiload outside Reno, thence eastward to Salt Lake City, and then southwest to Las Vegas on the rail link to Los Angeles! In recent years the mine had still produced magnesia (MgO) for refractory brick, but even that has fizzled. It closed a couple of years ago. The ore mineral was magnesite (MgCO3, magnesium carbonate), a product of local contact metamorphism of dolomite (CaMg(CO3)2). The left inset is a now-obsolete sign at the mine turnoff; the right is a telephoto view of the operations.