Fluorite – Minerva No. 1 Mine, Cave in Rock, Hardin Co., Illinois, USA
 An excellent fluorite specimen with highly lustrous, complexly colored crystals and intense phantoms. The sharp-edged phantoms of bright yellow, blue, and violet are characteristic of the finest fluorite specimens from the Minerva #1 Mine. The cubic crystals have a wonderful surface structure that flattens toward the edges.
 A beautiful classic from a well-known locality that is unfortunately no longer in operation and therefore cannot produce new specimens of this unique quality.