Minerva No. 1 Mine, Cave-in-Rock, Hardin Co., Illinois, USA
A beautifully zoned fluorite form the southern IL fluorspar district. The front and sides are etched, the contact is located on the lower back/ bottom. The color is actually nicer in person-- it has more of a cyan component that is somehow not picked up by the camera. There is a bit of edge wear, but the piece is as shown.