Fluorite
Calcium
Fluoride
CaF2
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.
Physical Properties of Fluorite
| Color |
White or colorless,
purple, blue, blue-green, yellow, brownish-yellow, or red. |
| Crystal habit |
Occurs as well-formed coarse
sized crystals. Also as massive - granular. |
| Crystal system |
Isometric 4/m bar 3 2/m. |
| Cleavage |
[111] Perfect, [111] Perfect,
[111] Perfect. |
| Fracture |
Uneven |
| Mohs Scale hardness |
4 |
| Luster |
Vitreous |
| Refractive index |
1.433-1.435 |
| Streak |
White |
| Specific gravity |
3.18 |
| Fusibility |
3 |
| Solubility |
Slightly in water |
| Other |
Sometimes phosphoresces when
heated or scratched. Other varieties fluoresce beautifully. |
Uses of Fluorite
The uses of fluorite are as follows:
- Ornamental
uses.
- As
flux in the manufacture of steel.
- In
the making of opalescent glass.
- As
enamels for cooking utensils.
- As
hydrofluoric acid.
- As
elements in place of glass in some high performance telescopes and
camera lens.
Occurrences of Fluorite
Fluorite may occur as vein deposit, particularly with metallic
minerals. It often forms a part of the gangue, "host-rock"
without any worth, and may be associated with galena, sphalerite,
barite, quartz, and calcite.
-
Germany
- Austria
- Switzerland
- England
- Norway
- Mexico
- Canada
- Ontario
- USA
- Missouri, Oklahoma, Illinois, Kentucky, Colorado, New Mexico,
Arizona, Ohio, New Hampshire, and New York.
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