Fluorite
WHAT IS IT?
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Chemical composition: calcium fluoride (CaF2)
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Crystallization: isometric cubic (most common), octahedral & complex isometric (less common)
(crystal twinning is common) -
Hardness: 4
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Impurities produce colorful samples
Most common colors: purple, blue, green, yellow, colorless
Less common: pink, red, white, brown,black - Formed in hydrothermal veins usually those containing lead and zinc
- Found in greisens, granites, pegmatites & as a cementing material in sandstones
OTHER FACTS
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First identified by the geologist J.B. Jukes on the Burin Peninsula (Newfoundland) in 1843
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Pure fluorite is transparent to visible & uV light
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The color of fluorites will change when exposed to radiation
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The element fluorine derived it's name from fluorite (from which it was first produced)
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Fluorite is the origin of the word "fluorescence".
In 1852, it was discovered that some fluorites glow when exposed to uV light.
WHERE IS IT FOUND?
- 230 MT of world reserves with the largest deposits in South Africa (41 MT), Mexico (32 MT) & China (24 MT)
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The largest producers (annually) are: China (3 MT), Mexico (1 MT), Mongolia (0.45 MT), Russia (0.22 MT),
South Africa (0.13 MT), Spain (0.12 MT) & Namibia (0.11 MT) - The largest single crystal of fluorite was found at Dalnegorsk, Russia and weighs 16 tons & is 7 feet in length
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In Washington State minor deposits are found in the following counties: Chelan, Ferry, Grant, Lincoln, Okanogan, Skamania, Snohomish,
Stevens.
WHAT IS IT USED FOR?
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Ornamental & lapidary uses
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The Romans used fluorite for carvings
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Used as a flux for iron smelting
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Used for manufacturing glass
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Enameled products
- Chemical manufacturing (such as hydrofluoric acid - a glass etchant)
- Microscope & telescope lenses
- Used to manufacture the lenses in the steppers used for integrated circuit lithography,
because of it's low light dispersion ( low change in refraction index with wavelength) - Used for infrared & uV windows in scientific instruments
