One of fluorite's ingredients, the active element fluorine, is a violent poison that is also the most active of elements, capable of
eating through glass and metal. Discovery and isolation of this element caused the death and permanent injury of many
scientists. Another fluorine compound, hydrofluoric acid, is used to etch glass, dissolve quartz, and other minerals.
But as a crystal/stone, fluorite is a harmless mineral of great beauty and variety, ranging from purple, yellow,
green, blue, red, and all shades in between. It forms naturally in crystals that range from simple cubes to
complex combinations showing as many as 48 faces or more.
Though generally too soft to be used for fine jewelry, having a hardness 4.0 on the Moh's scale, it is extensively
used in carvings, in interior decorating, and personal jewelry and art objects. Sold commercially as fluorspar, it is usually
quite pure, but as much as 20 percent yttrium or cerium may replace the calcium content. It is one of the most popular
minerals among collectors because it is a common mineral that can be obtained in a full range of prices. And, of course,
there is its beauty and metaphysical uses...
Fluorite was once plentiful in the Illinois area but the vast deposits once mined there are largely depleted now.
Some of the worlds most prized fluorite specimens come from Swiss and French Alp deposits where
crystals occur as simple octahedrons and range in color from a delicate pink to a rich red.
Fluorite is used in opalescent glass, and at one time, Blue John, a variety from Derbyshire, England, was widely used in ornamental vases and other objects. It is used as a flux in metallurgical processes, like open-hearth steel and steel enamelware, in the production of hydrofluoric acid, in the refining of lead and antimony, and in the manufacture of high-octane fuels.
Because of its low index of refraction and low dispersion, the rare, clear crystals of the mineral are valuable in
making lenses and prisms for optical systems using ultraviolet light.
Cryolite is a fluoride of aluminum and sodium.