Gem Library

BUYER’S OVERVIEW:
Fluorite is considered to be a semi-precious gemstone. Relatively abundant in nature, clear, large, natural stones are available. Fluorite is well known and highly prized for its glassy luster and rich colors. Colors range from Fluorites hallmark color purple (having the same rich intensity as amethyst), to blue, green, yellow, brown, pink, colorless, black and reddish orange. The blue, green and yellow Fluorites tend to be very saturated in color and the brown variety found in Ohio has a distinctive iridescence. Fluorite is occasionally found with mixed zones of color or with distinct color bands making those rare gems that command attention.

COLOR:
Fluorite comes in a wide range of colors including; green, blue, violet, purple, pink, yellow, brown and colorless. It can also be found with mixed zones of color or with distinct color bands however this is rare.

APPEARANCE:
Transparent to translucent, Fluorite is usually included.

SIZE RANGE:
1 to 125 carats; large specimens are available.

TYPICAL CUTTING STYLES:
Transparent: most cutting styles are available.
Translucent: cabochons, beads and carvings

POSSIBLE ENHANCEMENTS & TREATMENTS:
Occasionally, heat treatment is used to improve color. This treatment is undetectable and has excellent stability.

HARDNESS:
4 on the Mohs scale.

BEST USE OF THE GEMSTONE:
Fluorite is not a strong gemstone and as such, earrings, pendants, pins, and tie tacks are probably the safest choice for this stone. Rings should be limited to occasional wear and the stones should be set with a protective setting. Avoid rough handing.

CARE & CLEANING:
It is best to never expose colored gemstones to cleaning solvents or chemicals of any kind.
Common cleaning methods include:
Ultrasonic: never
Steamer: never (very heat sensitive)
Warm soapy water: safe
Reaction to Chemicals: decomposed by sulfuric acid
Reaction to Heat: very heat sensitive
Stability to Light: generally stable after prolonged exposure to sunlight or UV light.

INTERESTING FACTS ABOUT THIS GEMSTONE:
The origin of the name Fluorite comes from the Latin word “fluere” which means to flow. Fluorite has a very low melting point and because of this the mineral version is used as a flux in the aluminum and steel making process. It was originally referred to as Fluorospar by miners and that name is still in use today. Fluorite is also used as a source of Fluorine for hydrofluoric acid and fluoridated water.

Many types of Fluorite glow under ultraviolet light, they're said to be "fluorescent." (a term derived from the name of the stone, the first known substance to exhibit this property).  Typically they fluoresce blue but other fluorescent colors include yellow, green, red, white and purple. The most unique luminescent property of Fluorite is thermoluminescence. This is a very rare phenomenon in which the substance glows when heated. A variety of Fluorite known as chlorophane which means “to show green”, will glow a green to blue-green from the heat of your hand or when placed on the heat of an electric stove. Once seen, the glow will fade and can no longer be seen in the same specimen again.

Most specimens of Fluorite have a single color, but a small percentage of crystals have multiple colors found in zones or well defined bands. The banded Fluorite has a fantastic look, almost too good to be naturally created.

The ancient Egyptians used Fluorite to carve statues and scarabs and the Chinese have used it in carvings for over 300 years. Fluorite is also used in high performance telescopes and camera lens elements where it allows crisp images of astronomical objects even at high power. Nikon has manufactured at least one all fluorite element camera lens (105 mm f/4.5 UV) for the production of ultraviolet images.

The United States is a large producer of fluorite and in 1965 Illinois named fluorite the state mineral. At that time, Illinois was the largest producer of fluorite if the United States; however, the last Illinois mine closed in 1995. One of the most famous of the older Fluorite mine locations is Derbyshire, England where the famous Derbyshire Blue John, a purple-blue fluorite originated. The name derives from the French “bleu et jaune” (blue and yellow) and was mined during the 19^th century. Blue John had great ornamental value but is now very scarce and very little is mined. Currently, there are a few areas in the eastern United States and Pakistan that produce gem quality Fluorite.

DESIGNATION:
This gem has a long history but has no traditions currently associated with it.

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