Fluorite, Rosiclare Level Cross-Cut Orebody, Minerva #1 Mine, Ozark-Mahoning Company, Cave-in-Rock District, Southern Illinois, Mined ca. 1990, Koster Collection, Medium Cabinet 3.5 x 7.5 x 13.0 cm, $1200. Online 3/18. SOLD
Zoned purple, yellow and pale blue fluorite exhibiting pronounced dissolution/etched features caused by preferential dissolution of barite. The fluorite was coated with hydrocarbons and subsequently cleaned to reveal the glassy surface. Note yellow fluorite crystals show classic distorted forms from contemporaneous growth with barite. Condition: excellent. Provenance: purchased in district by Ross Lillie ca. 1990, sold to Sam Koster ca. 1990; consigned to Ross Lillie 2016. Beautiful when backlit.