Minerva Mine No. 1, Cave-in-Rock Dist., Illinois, USA
14 cm tall x 11.5 cm wide
Mined 1992
Ex-collection Ross Lillie
Illinois fluorite is renowned for its range and intensity of colors. It is considered by many to be the ultimate fluorite locality. Most fluorite from Illinois lack matrix and only rarely does it have accessory species. This rare example has both.
The fluorite crystals are classic cubes with deep rich colors and sharp delineated zoning. The center of each crystal is amber orange, stepping up into shades of purple, and finally terminating in an aqua blue. These colorful crystals sit along the edge of a creamy white matrix of barite. At the top of the specimen is a secondary growth of clear and pale yellow scalenohedral crystals of calcite. The combination of these three different minerals creates a specimen of great rarity and beauty.
The Minerva Mine, along with all of the other fluorite mines in Illinois, have been closed for at least the past 20 years. It is doubtful that they will ever reopen.