FLUORITE

"The Most Colorful
Mineral in the World"


  • Chemistry: CaF2, Calcium Fluoride
  • Class: Halides
  • Uses: As a flux (hence the name) in iron smelting, a rare gemstone, a source of fluorine, as special optical lenses and a popular mineral specimen.
  • Physical Properties.
  • Specimens

Fluorite is a mineral with a veritable bouquet of brilliant colors. Fluorite is well known and prized for its glassy luster and rich variety of colors. The range of common colors for fluorite starting from the hallmark color purple, then blue, green, yellow, colorless, brown, pink, black and reddish orange is amazing and is only rivaled in color range by quartz. Intermediate pastels between the previously mentioned colors are also possible. It is easy to see why fluorite earns the reputation as "The Most Colorful Mineral in the World".

The many colors of fluorite are truly wonderful. The rich purple color is by far fluorite's most famous and popular color. It easily competes with the beautiful purple of amethyst. Often specimens of fluorite and amethyst with similar shades of purple are used in mineral identification classes to illustrate the folly of using color as the sole means to identify minerals.

The blue, green and yellow varieties of fluorite are also deeply colored, popular and attractive. The colorless variety is not as well received as the colored varieties, but their rarity still makes them sought after by collectors. A brown variety found in Ohio and elsewhere has a distinctive iridescence that improves an otherwise poor color for fluorite. The rarer colors of pink, reddish orange (rose) and even black are usually very attractive and in demand.

Most specimens of fluorite have a single color, but a significant percentage of fluorites have multiple colors and the colors are arranged in bands or zones that correspond to the shapes of fluorite's crystals. In other words, the typical habit of fluorite is a cube and the color zones are often in cubic arrangement. The effect is similar to phantomed crystals that appear to have crystals within crystals that are of differing colors. A fluorite crystal could have a clear outer zone allowing a cube of purple fluorite to be seen inside. Sometimes the less common habits such as a colored octahedron are seen inside of a colorless cube. One crystal of fluorite could potentially have four or five different color zones or bands.

To top it all off, fluorite is frequently fluorescent and, like its normal light colors, its fluorescent colors are extremely variable. Typically it fluoresces blue but other fluorescent colors include yellow, green, red, white and purple. Some specimens have the added effect of simultaniously having a different color under longwave UV light from its color under shortwave UV light. And some will even demonstrate phosphorescence in a third color! That's four possible color luminescence in one specimen! If you count the normal light color too. The blue fluorescence has been attributed to the presence of europium ions (Eu +2). Yttrium is the activator for the yellow fluorescence. Green and red fluorescent activation is not exactly pinned down as of yet, but may be due to the elements already mentioned as well as other rare earth metals; also manganese, uranium or a combination of these. Even unbonded fluorine trapped in the structure has been suggested. The word fluorescent was derived from fluorite since specimens of fluorite were some of the first fluorescent specimens ever studied. The naming followed the naming precedence set by opalescence from opal; ergo fluorescence from fluorite.

Another unique luminescent property of fluorite is its thermoluminescence. Thermoluminescence is the ability to glow when heated. Not all fluorites do this, in fact it is quite a rare phenomenon. A variety of fluorite known as "chlorophane" can demonstrate this property very well and will even thermoluminesce while the specimen is held in a person's hand activated by the person's own body heat (of course in a dark room, as it is not bright enough to be seen in daylight). The thermoluminescence is green to blue-green and can be produced on the coils of a heater or electric stove top. Once seen, the glow will fade away and can no longer by seen in the same specimen again. It is a one shot deal. Chlorophane (which means to show green) is found in very limited quantities at Amelia Court House, Virginia; Franklin, New Jersey and the Bluebird Mine, Arizona, USA; Gilgit, Pakistan; Mont Saint-Hilaire, Quebec, Canada and at Nerchinsk in the Ural Mountains, Russia.

Fluorite has other qualities besides its great color assortments that make it a popular mineral. It has several different crystal habits that always produce well formed, good, clean crystals. The cube is by far the most recognized habit of fluorite followed by the octahedron which is believed to form at higher temperatures than the cube. Although the cleavage of fluorite can produce an octahedral shape and these cleaved octahedrons are popular in rock shops the world over, the natural (e.g. uncleaved) octahedrons are harder to find.

A rarer habit variety is the twelve sided dodecahedron however it is never seen by itself and usually modifies the cubic crystals by replacing the edges of the cube with one flat face of a dodecahedron. The tetrahexahedron is a twenty four sided habit that is also seen modifying the cubic habit. But instead of one face replacing each cubic edge, two faces modify the cube's edges. Occasionally combinations of a cube, dodecahedron and tetrahexahedron are seen producing an overall cubic crystal with no less that three minor parallel faces replacing each cubic edge. A fifth form is the hexoctahedron which modifies the cube by placing six very minor faces at each corner of the cube. Twinning is also common in fluorite and symmetrical penetration twins, especially from Cumberland England are much sought after by collectors.

Fluorite, as mention above, has octahedral cleavage. This means that it has four identical directions of cleavage and when cleaved in the right ways can produce a perfect octahedral shape. Many thousands of octahedrons are produced from massive or large undesirable crystals of fluorite (hopefully!) and are sold in rock shops and museum gift shops at a small cost. Fluorite mine workers are reported to sit down at lunch breaks and cleave the octahedrons for the extra cash. The octahedrons are very popular due to their attractive colors, clarity, "diamond-shaped" and low costs, but to a serious collector they are nothing more than "cleavage fragments".

Fluorite not only is attractive in its own right but is often associated with other attractive minerals. Fluorite crystals will frequently accompany specimens of silver gray galena, brassy yellow pyrite, chalcopyrite or marcasite, golden barite, black sparkling sphalerite, intricately crystallized calcite and crystal clear quartz, even amethyst.

The origin of the word fluorite comes from the use of fluorite as a flux in steel and aluminum processing. It was originally referred to as fluorospar by miners and is still called that today. Fluorite is also used as a source of fluorine for hydrofluoric acid and fluorinated water. The element fluorine also gets its name from fluorite, fluorines only common mineral. Other uses of fluorite include an uncommon use as a gemstone (low hardness and good cleavage reduce its desirability as a gemstone), ornamental carvings (sometimes misleadingly called Green Quartz) and special optical uses.

Fluorite is the most popular mineral for mineral collectors in the world, second only to quartz. Every mineral collection owned by even the newest and youngest of mineral collectors must have a specimen of fluorite. Fluorite is by far one of the most beautiful and interesting minerals available on the mineral markets.

PHYSICAL CHARACTERISTICS:

  • Color is extremely variable and many times can be an intense purple, blue, green or yellow; also colorless, reddish orange, pink, white and brown. A single crystal can be multi-colored.
  • Luster is vitreous.
  • Transparency: Crystals are transparent to translucent.
  • Crystal System: Isometric; 4/m bar 3 2/m
  • Crystal Habits include the typical cube and to a lesser extent, the octahedron as well as combinations of these two and other rarer isometric habits. Always with equant crystals; less common are crusts and botryoidal forms. Twinning also produces penetration twins that look like two cubes grown together.
  • Cleavage is perfect in 4 directions forming octahedrons.
  • Fracture is irregular and brittle.
  • Hardness is 4
  • Specific Gravity is 3.1+ (average)
  • Streak is white.
  • Other Characteristics: Often fluorescent blue or more rarely green, white, red or violet and may be thermoluminescent, phosphorescent and triboluminescent.
  • Associated Minerals are many and include calcite, quartz, willemite, barite, witherite, apatite, chalcopyrite, galena, sphalerite, pyrite and other sulfides.
  • Notable Occurrences include in addition to those mentioned above Cumberland, England; Spain; China; Brazil; Morocco; Bancroft, Ontario, Canada; Naica, Chihuahua, Mexico; Germany; Elmwood, Tennessee; Rosiclare, Illinois; Fort Wayne, Indiana; Pugh Quarry and Wood County, Ohio; Nancy Hanks Mine, Colorado and many other USA localities as well as many other localities from around the world.
  • Best Field Indicators are crystal habit, color zoning, hardness (harder than calcite, but softer than quartz or apatite), fluorescence and especially the octahedral cleavage.




















This Site Awarded
Available FLUORITE specimens:
FLUORITE specimen FLU-203
$ 200.00 -50% = $ 100.00
Dims: 11.55x4.80x2.95in (29.34x12.18x7.48cm) .... Wt: 160oz (4537g) .... Loc: Xianohualino, Hunan, China
This large specimen displays hundreds of pale blue-green cubes and rectangles of fluorite, under a druze that appears to be quartz crystals with an unknown white coating. The fluorite fluoresces blue under short-wave UV.
no photo
FLU-203
$ 100.00
no photo
FLUORITE specimen FLU-204
$ 300.00 -50% = $ 150.00
Dims: 6.1x3.5x4.7in (15.5x8.8x11.9cm) .... Wt: 96oz (2728g) .... Loc: Rogerley Mine, England
Mostly fluorite, this specimen displays numerous cubes of the green color so characteristic of the Rogerly mine, plus others that are pale, or cloudy, or tinted somewhat blue. Several crystals appear green and exhibit blue color zones. All of the crystals fluoresce blue under shortwave UV.
no photo
FLU-204
$ 150.00
no photo
FLUORITE specimen FLU-183
$ 150.00 -20% = $ 120.00
Dims: 4.6x2.9x3.0in (11.6x7.3x7.7cm) .... Wt: 21.6oz (612g) .... Loc: Glory Hole, Bingham area, Hansonburg Mining District, Socorro County, New Mexico, USA
Two sides of this specimen are covered with centimeter-sized (approximately) cubes of blue fluorite. They rest upon a thin layer of small light-blue fluorite crystals, which fluoresce a pale purple. Many of the larger crystals have that unusual diagonal surface etch pattern.
no photo
FLU-183
$ 120.00
no photo
FLUORITE specimen FLU-184
$ 25.00 -20% = $ 20.00
Dims: 1.95x1.27x0.86in (4.95x3.22x2.20cm) .... Wt: 2.19oz (62.0g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
Most of the mass of this Rogerly specimen is galena, which is accompanied by dozens of small green fluorite cubes and a sparkly druze of quartz crystals. A dental pick could easily reveal more of the crystals.
no photo
FLU-184
$ 20.00
no photo
FLUORITE specimen FLU-185
$ 38.00 -20% = $ 30.40
Dims: 2.78x1.98x1.80in (7.06x5.02x4.56cm) .... Wt: 6.8oz (192g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
This fluorite specimen is from the Rogerly Mine, and shows the typical blue fluorescence noted from that location. Most of the fluorite cubes are coated with a druze of quartz crystals.
no photo
FLU-185
$ 30.40
no photo
FLUORITE specimen FLU-179
$ 72.00 -20% = $ 57.60
Dims: 3.02x2.04x0.39in (7.67x5.18x1.00cm) .... Wt: 2.78oz (78.7g) .... Loc: Rio Arriva County, New Mexico, USA
This is a specimen of botryoidal fluorite, likely formed as a rapidly growing crust on a host rock (not present). It is rather transparent, with areas of purple and yellow, with a pattern that differs somewhat from the front-illuminated appearance which shows a rough, mottled appearance with areas of a golden and/or green irridescence. I like it.
no photo
FLU-179
$ 57.60
no photo
FLUORITE specimen FLU-187
$ 38.00 -20% = $ 30.40
Dims: 3.47x1.94x1.12in (8.82x4.93x2.85cm) .... Wt: 6.3oz (177g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
On a relatively flat substrate, this specimen displays more than a dozen mostly transparent green fluorite cubes which glow blue under ultraviolet light. Accompanying them are a similar number of galena crystals which look black and rough from some angles but bright and silvery from others.
no photo
FLU-187
$ 30.40
no photo
FLUORITE specimen FLU-188
$ 30.00 -20% = $ 24.00
Dims: 3.63x1.68x1.19in (9.22x4.27x3.03cm) .... Wt: 6.1oz (172g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
Most of the mass of this specimen is in a single large somewhat transparent green fluorite crystal. Naturally, all of the fluorite glows a bright blue under UV light. While originally coated with a druze of calcite, most of that has been chipped away.
no photo
FLU-188
$ 24.00
no photo
FLUORITE specimen FLU-189
$ 53.00 -20% = $ 42.40
Dims: 3.15x2.26x0.69in (8.01x5.74x1.76cm) .... Wt: 2.61oz (74.0g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
This Rogerly specimen is quite aesthetic - it presents very well, and looks much better in person than these images suggest. In additino to the fluorite cubes and quartz druze, it displays several small galena crystals.
no photo
FLU-189
$ 42.40
no photo
FLUORITE specimen FLU-190
$ 45.00 -20% = $ 36.00
Dims: 2.79x2.32x1.18in (7.09x5.88x3.00cm) .... Wt: 6.8oz (191g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
This is essentially a single huge fluorite specimen. It is somewhat transparent, largely coated with a druze of calcite, and of course fluoresces blue under UV.
no photo
FLU-190
$ 36.00
no photo
FLUORITE specimen FLU-197
$ 65.00 -20% = $ 52.00
Dims: 4.71x4.45x0.96in (11.97x11.30x2.44cm) .... Wt: 18.5oz (525g) .... Loc: Xian Hu Lin Mine, Hunan, China
Nice, pale aqua-green-colored crystals of fluorite rest on a slab of more fluorite, with a backdrop of a pretty white druze that appears to be quartz crystals mostly coated with a thin white layer of something. The fluorite crytals are transparent cubes with an interesting surface pattern.
no photo
FLU-197
$ 52.00
no photo
FLUORITE specimen FLU-191
$ 28.00 -20% = $ 22.40
Dims: 2.77x1.72x1.42in (7.03x4.37x3.61cm) .... Wt: 4.6oz (129g) .... Loc: Rogerly Mine, Frosterley, Durham County, England
This Rogerly fluorite specimen has relatively small crystals, most of which are coated by a sparkly quartz druze. I'm certain more of the fluorite could be exposed, but it seems adequately aesthetic to me.
no photo
FLU-191
$ 22.40
no photo
FLUORITE specimen FLU-198
$ 50.00 -20% = $ 40.00
Dims: 4.44x3.50x2.04in (11.27x8.89x5.19cm) .... Wt: 23.2oz (656g) .... Loc: Xian Hu Lin Mine, Hunan, China
Only a few fluorite cubes are exposed on this specimen, the bulk of which is a host rock (which includes additional fluorite) which has been completely coated with a white druze of quartz crystals, white because of a thin coating of something else. A loupe reveals that the quartz crystals often have holes at their tips, but closer inspection shows that the holes are in the white coating, and the transparent quartz crystal inside is exposed.
no photo
FLU-198
$ 40.00
no photo
FLUORITE specimen FLU-181
$ 120.00 -20% = $ 96.00
Dims: 5.47x2.99x0.56in (13.90x7.60x1.41cm) .... Wt: 7.0oz (197g) .... Loc: Rio Arriba County, New Mexico, USA
This is a beautiful specimen of botryoidal flourite. It is difficult to decide what the actual color is (it might be green, or yellow, or brown, or varied) since the fluorite is, at best, translucent, and moreover is covered by an irridescent coating of some metal sulfide (possibly bornite or even just chalcopyrite). The colors are blues and greens and reds and yellows, and it looks good to the bare eye, and awesome when examined using a loupe. The areas that superficially appear to be damage just look like additional crystallization when viewed under magnification.
no photo
FLU-181
$ 96.00
no photo
see this List of ALL specimens including SOLD ones

 

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