Purple/Yellow Cubic Fluorite & Calcite on Matrix - Illinois

This is a beautiful matrix of purple and yellow cubic fluorite with calcite from the Cave-In-Rock district of Harden County, Illinois. Although there are some natural abrasions, the crystals are in overall great shape. The specimen has been cut so that it will sit on a flat surface for an impressive display.

Fluorite is a halide mineral comprised of calcium and fluorine, CaF2. The word fluorite is from the Latin fluo-, which means "to flow". In 1852 fluorite gave its name to the phenomenon known as fluorescence, or the property of fluorite to glow a different color depending upon the bandwidth of the ultraviolet light it is exposed to. Fluorite occurs commonly in cubic, octahedral, and dodecahedral crystals in many different colors. These colors range from colorless and completely transparent to yellow, green, blue, purple, pink, or black. Purples and greens tend to be the most common colors seen, and colorless, pink, and black are the rarest.

Archaeological discoveries near the Cave-In-Rock mining district of beads and other ornaments made of fluorite have placed the use of the stone to about 900 years ago when the land was inhabited by the Native Mississippian Americans. Early European settlers mining for galena in the 1830's discarded the fluorite as the lead they sought was more valuable at the time. In the 1880's it was discovered that fluorite was very useful in a new steel-furnace technology, and demand increased considerably, and several commercial fluorite mining companies appeared in Illinois/Kentucky region.

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