Fluorite occurs commonly as cubic, octahedral and dodecahedral crystals in highly variable colors ranging from colorless and completely transparent to yellow, green, blue, purple, pink or black. Crystals may be large and penetration twins are fairly common. Fluorite often fluoresces with a blue or violet color in ultraviolet light.
More information on the fluorite and mines of Hardin County, Illinois is available.
Rocks from Ron Zeilstra's Collection
bkeller@rockhounds.com 4/12/96