ABSTRACT This article rhetorically investigates a missing mining report known as the Jackling-Gemmell Report. Supposedly published in September 1899, this report was the first to scientifically rationalize porphyry, or open-pit, mining methods. Based on my analysis of thousands of archival records at Stanford University’s Daniel Jackling Collection, I argue that this textual absence is sutured by the rhetorical presence of mythopoeia wherein Daniel Jackling has become mythologized as the alchemist that transformed useless rock (i.e., mountains) into pure copper for modern technology. In my analysis of relevant books, letters, and reports, I complicate the textual agency of this alleged report and show how Jackling himself created a powerful public persona as a prophetic hero that predicted the commercial success of porphyry mining. I offer the concept alchemical rhetoric to emphasize how rhetors and rhetoricians create different meanings, identities, and realities from rhetorical resources within an extractive worldview.