Gypsum

Unknown Owner

A beautiful cluster of gypsum crystals coming off a common matrix. In great condition. Complete all around, this is excellent for this locality and species. The specimen was collected in 1949, most likely from 15 level, 1525 feet below the surface of the earth.The Bristol Mine, located in Crystal Falls within the Iron River-Stambaugh district of Iron County, Michigan, was one of the most productive and enduring iron mines on the Menominee Range. Geologically, the mine exploited the Riverton Iron Formation, a Paleoproterozoic sequence where tectonic folding and faulting created structural traps for mineral-rich fluids. These fluids enriched the primary iron carbonate rocks into massive bodies of high-grade hematite and goethite. Historically, the mine was opened in 1889 and saw several periods of expansion under various operators, most notably the Inland Steel Company. Known for its deep underground workings and impressive vertical shafts, the Bristol Mine remained a vital industrial contributor for over half a century. It operated continuously through the peak of the American steel era until its final closure in 1969. Today, the site is remembered as a cornerstone of the Crystal Falls mining community and a classic locality for studying the complex structural geology of the Michigan iron districts.