Fat Jack Mine

The Fat Jack Mine sits in the rugged Bradshaw Mountains near Crown King, Arizona — a remote mining district that saw its first prospectors during the late 1800s gold rush. The mine takes its name from "Fat Jack," a larger-than-life prospector who worked claims in the Crown King district. Like many colorful figures of Arizona's territorial mining era, Fat Jack left his mark on the landscape itself — his name permanently attached to the workings he carved into the mountainside.

Originally developed for its lead, silver, and gold deposits, the Fat Jack was a working metal mine through the early 20th century. The Bradshaw Mountains district produced significant tonnage of base metals, and the Fat Jack contributed to that output alongside neighboring operations like the War Eagle, Tiger, and Crown King mines.

The mine's second life began when mineral collectors recognized the exceptional quality of its secondary mineral specimens — particularly wulfenite. Fat Jack wulfenite quickly earned a reputation as some of the finest from Arizona, with crystals displaying the distinctive orange-red tabular habit and adamantine luster that collectors prize. Specimens from the Fat Jack have found their way into museum and private collections worldwide.

In June 2025, Borussia Minerals acquired the Fat Jack Mine, continuing the tradition of careful specimen recovery while preserving this important mineralogical locality for future generations.

Recent work at the mine has yielded a significant new discovery. Details will be announced soon.

The Fat Jack Mine is situated in Precambrian metamorphic rocks of the Bradshaw Mountains, where lead-zinc-silver mineralization occurs in oxidized zones along fault structures. The secondary mineral assemblage includes exceptional wulfenite (lead molybdate), along with vanadinite, mimetite, and cerussite.

The distinctive orange-red color of Fat Jack wulfenite results from trace chromium substituting for molybdenum in the crystal structure. Crystals typically form as thin tabular plates, often perched dramatically on matrix or intergrown in parallel clusters.

Recent work continues to expand the known mineral diversity of this historic locality.