The State of Illinois has historically been the largest producer of fluorite in the United States.
Historically, some varieties of fluorite have been used for ornamental purposes.
Fluorite crystals are isometric with a cubic habit, though octahedral and more complex isometric forms are not uncommon.
The fluorescent color of fluorite is largely dependent on where the original specimen was located.
Fluorite gives its name to the property of fluorescence, as many (but not all) samples of this mineral produce a strong glow when exposed to ultraviolet light.
Pig iron is later reduced to steel, using convertors.
Light dispersion through fluorite is very low, compared to dispersion through ordinary glass.
Fluorite (also called fluorspar) is a mineral composed of calcium fluoride (chemical formula CaF2).
Exposure tools for the semiconductor industry make use of fluorite for optics at the wavelength of 157 nanometers (nm).
Given the low dispersion of light through fluorite, this mineral is used instead of glass in high-performance telescopes to produce crisp images of astronomical objects even at high power.
Fluorite may occur as a vein deposit, especially with metallic minerals, where it often forms part of the gangue.
In 1965, the Illinois General Assembly passed a resolution declaring fluorite the official state mineral.
Recently, deposits in China have produced fluorite with similar coloring and banding to the classic Blue John stone.
The name fluorite is derived from the Latin word fluo, meaning "flow," in reference to its use as a flux.
One of the most famous sites for the excavation of fluorite has been the Blue John Cavern in Castleton, Derbyshire, England.
Fluorite is a unique material in that it has high transparency at this wavelength.