Fluorite from the Illinois-Kentucky Fluorspar District (IKFD) has captured the hearts of mineral collectors for decades. In recent years, Illinois fluorite has become quite the craze, especially with young collectors, as gone are the days of being able to purchase “spar” by the pound. Recently, the U.S. government classified fluorspar as a critical mineral with numerous federally funded projects across the district to assess for critical minerals.

This presentation aims to introduce the geology and discuss the prospect of critical minerals while taking a walk through the history of the IKFD and looking at some exceptional specimens along the way.

Jared T. Freiburg is the Illinois State Geological Survey’s mineral resource geologist and leads the Critical and Strategic Minerals Section. He is also the president of Saga Minerals, Inc.

Jared received his B.S. and M.S from the University of Illinois Urbana-Champaign and his PhD at the University of Greifswald in Germany. His research interests include sedimentology, diagenesis, Precambrian geology, and Mississippi Valley-Type mineral deposits. He specializes in sedimentary petrography and employs a variety of microscopy and geochemical techniques in his research.

His current research involves understanding the evolution of the Illinois Basin which includes events of rifting and magmatism. He is presently working in and around the Illinois-Kentucky Fluorspar District as part of the United States Geological Survey led Earth Mapping Resources Initiative (Earth MRI), part of a federal strategic plan to improve the nations understanding of domestic critical mineral resources.