Fluorite with Malachite, Chalcopyrite, Calcite

specimen number:
2312225

location:
Denton Mine, Hardin Co., Illinois, USA

description:
Gorgeous color zoned amber and bluish purple cubic crystals of fluorite in a cluster hosting small crystals of chalcopyrite, some of these with a green alteration of malachite present. This is in really good condition. This was mined in August, 1994 just before the permanent closure of this famous locality.

The Denton Mine, located in Hardin County, Illinois, was put into operation in 1981 as part of the famous Illinois-Kentucky Fluorspar Mining District. It was developed to extract valuable mineral resources from deep underground, reaching a depth of 640 feet. Geologically, the mine is situated within the Cave-in-Rock subdistrict, where mineralization occurred through hydrothermal processes involving mineral-rich fluids moving along fault lines and fractures. These hot solutions reacted with Paleozoic limestone and sandstone host rocks, resulting in extensive bedding replacement and cavity fillings. The Denton Mine became particularly renowned among geologists and collectors for producing world-class specimens of fluorite, often featuring striking blue cubic crystals, along with associated minerals such as barite, calcite, sphalerite, and galena.

Questions about this specimen?
Send an email or call us: 314-341-1811.