Fluorite with Galena, Sphalerite - image 1

Fluorite with Galena, Sphalerite

Unknown Owner

Classic rosy purple translucent semi lustrous crystals of fluorite measuring to 3.0 cm on edge acrostic crystallized lustrous black sphalerite matrix with crystals of galena to 2.3 cm on edge. In good condition, a wonderful large combination piece for this old locality. At one time this was part of the collection of Gabriele Heinicke.The Hill-Ledford Mine, situated in the Cave-in-Rock District of Hardin County, Illinois, was a significant operation within the Illinois-Kentucky Fluorspar District known for its high-quality bedded replacement deposits. Geologically, the mine exploited mineralized zones where fluorine-rich hydrothermal fluids interacted with the Mississippian-aged Spar Mountain Member of the Ste. Genevieve Limestone, resulting in the replacement of carbonate rock with fluorite. These deposits typically formed horizontal ore bodies, or mantos, which produced exceptional specimens of yellow and purple fluorite, frequently associated with sphalerite and minor galena. Historically, the Hill-Ledford was active during the mid-20th century, with its most intensive period of production occurring from the 1940s through the 1950s under the management of the Ozark-Mahoning Company and other regional operators. The mine contributed significantly to the United States' domestic supply of acid-grade fluorspar during and after World War II. Today, while the underground workings are inaccessible, the mine is highly regarded by mineralogists for the classic, sharp cubic crystals that were recovered during its peak years of operation.