Fluorite is a mineral that comes in a variety of colors and may be polished and faceted. However, its use as a gemstone is limited by its fragility. Fluorite forms under various conditions, in lead and silver veins, where it is produced by hypothermal precipitation, as beds and cavities in sedimentary rocks, in hot spring deposits, and in pegmatite. Associated minerals include apatite, barite, calcite, chalcopyrite, galena, pyrite, quartz, sphalerite, willemite and witherite.
Fluorite has a wide range of industrial uses, as a flux in iron smelting, as a source of fluorine and hydrofluoric acid, in ceramics, and in special optical lenses. The finest crystals make rare and attractive, if rather fragile, collectors items.
Fluorite is a fluoride of calcium. Its cubic crystals may appear in many shapes, cubes, octohedra, and dodecahedra are common. The mineral’s name is derived from the Latin fluere (“to flow”), this being a reference to its low melting point.
The colors of fluorite are variable. Blue, green, purple and yellow are most common, but some specimens are black, pink, red, or colorless. Most specimens have a single color, but a few have multiple colors arranged in bands or zones with shapes that correspond to the internal shape of the crystals. As a result, it is possible to see cubic crystals within crystals, each with a different color.
Fluorite is a fluorescent mineral. When subjected to ultraviolet light, cathode or X-rays, it will give off a strong pink or violet light of its own. However, fluorescence is not a consistent or reliable occurrence. The colors produced from one specimen to another, and some specimens will not fluoresce at all.
Very fine crystals are found lining large cavities of openings as large as 3 to 4 feet across at the Rock Candy Mine near Grand Forks. Green is the most common color, but purple and colorless varieties also occur. Other less noted areas are Whiteman Creek, Scuzzy Creek, Lumby, Hellroaring Creek, and Liard River Hot Springs.