At the 2026 RMGM Tucson Mineral & Fossil Show, collectors and mineral enthusiasts will have the rare opportunity to witness one of the most extraordinary native silver discoveries ever documented. Dr. Chris Osterman will present his findings from a modern rediscovery of Arizona’s legendary silver heritage, which bridges deep geological history, frontier lore, and cutting-edge mineral exploration.
Dr. Chris Osterman’s path to this discovery is grounded in rigorous science and decades of field experience. Trained initially as a mining engineer (BSc Mining Engineering – U of Idaho), Osterman went on to earn advanced degrees (MSc Geological Engineering – U of Arizona) in geology, culminating in a PhD in Geology from the Colorado School of Mines, focusing on sediment-hosted copper deposits in Namibia. His career, spanning over 30 years, has been defined by a rare combination of technical expertise and an instinct for identifying geological anomalies that others might overlook.
That instinct led him to Globe, Arizona, after a friend tipped him off to unusual silver finds in the area around 2019. What began as scattered reports from a group of metal detectorists quickly evolved into one of the most significant native silver discoveries of the modern era. The first breakthrough came when some local metal detectorists uncovered a 16-pound native silver nugget affectionately nicknamed ‘The Sweet Potato’. This initial rediscovery confirmed suspicions that something extraordinary lay beneath the surface.
Over the following two years, nearly 200 pounds of native silver were recovered in roughly two dozen pieces, ranging from a few grams to astonishing specimens weighing up to 120 pounds. Recognizing the significance of the find, a deal was struck to purchase and stake a claim to the property. The local metal detectorists, uninterested in traditional lode mining, stepped aside, clearing the way for what would become known as the 417 Project, named after the largest nugget ultimately recovered…