Large Golden Yellow Fluorite Cleaved Octahedron w/ Chalcopyrite from Cave-in-Rock, Illinois, USA

This is a very fine example of the gem variety of yellow fluorite “diamonds” with chalcopyrite inclusions from the last century. The piece has been cleaved from a larger piece of fluorite by a miner into the octahedron shape. It fluoresces pink under UV exposure. These fluorite “diamonds” became very hard to get today since the mines in the southern Illinois have been closed in the mid-1990s. Miners back then used to cleave these “diamonds” during their lunch breaks.