Fluorite Value, Price, and Jewelry Information

Do Fluorites Make Good Jewelry Stones?

Despite its low refractive index (RI), fluorite can take a high polish. This means faceted fluorites can show exceptional brilliance. Many fluorite crystals are also transparent.

Fluorites come in many colors, including colorless. Most available stones occur in shades of purple, blue, or green. Chrome green material from Colombia and pink gems are rare. Lapidaries can cut multi-colored gems (sometimes called "rainbow fluorites") from color zoned crystals, too.

Chemical impurities and natural irradiation contribute to fluorite's colorful varieties. Very rarely, some fluorites display a color change effect, from blue in daylight to purple or lavender in incandescent light. (Materials from England and Cherbadung, Switzerland have demonstrated this).

What is "Blue John" Fluorite?

For over 1,500 years, English artisans used Blue John or Derbyshire Spar as decorative material in vases, carvings, bowls, and so forth. This fluorite variety has bands of white, blue, violet, and reddish brown.

The Derbyshire deposits are nearly exhausted. However, a similar type of fluorite has been discovered in China.

Fluorite Properties

Some (but not all) fluorites display fluorescence under ultraviolet light (UV). Thus, confirming the presence of this property isn't diagnostic for identifying fluorite. However, this property is strongly associated with this gem. In fact, in 1852, the physicist Sir George Gabriel Stokes named this effect "fluorescence" after his studies of the mineral fluorite.

The presence of uranium (U) and rare-earth elements likely cause fluorite's fluorescence. However, sometimes organic inclusions (hydrocarbons) may be the cause.

Under longwave UV, fluorites can fluoresce yellow, blue, white, reddish, violet, or green.

Some fluorites exhibit phosphorescence under X-rays, a luminescence that lasts even after the light source is removed. Some material is also thermoluminescent, luminescing when heated.

Fluorescent fluorites with a coating of quartz crystals, Allenheads Mine, East Allendale, North Pennines, Northumberland, England, UK. © Rob Lavinsky, www.iRocks.com. Used with permission.

Chlorophane, a rare fluorite variety, shows phosphorescence and thermoluminescence, as well as triboluminescence. It luminesces when rubbed or held in your hand.

Are There Lab-Created Fluorites?

Lab-created fluorite in all its various colors is available. The optics industry especially values fluorite for the creation of high-quality lenses. Its low RI and low dispersion make it an ideal lens material. Not surprisingly, the search for cheaper synthetic production continues apace. Some manufacturers melt and mix high-purity natural fluorites with other materials to create high-quality lenses.

Currently, high production costs, combined with fluorite's low hardness and perfect cleavage, make synthetics an improbable choice for jewelry.

How Can You Distinguish Fluorites from Other Similar Gemstones?

Due to their considerable color range, you'll more likely find natural fluorites misidentified or misrepresented as other gems. For example, fluorites have been offered as amethysts, emeralds, and color change garnets.

Hardness testing, of course, is the easiest way to distinguish fluorites from these more popular and durable jewelry stones. However, conduct scratch testing only as a last resort and never on a finished gem. Fortunately, fluorite's very low RI and dispersion can help distinguish it from many other gems.

One of the more unusual examples of fluorite as a simulant has appeared in Asian markets. So-called "night glowing pearls" aren't pearls at all but often spherical fluorites, sometimes untreated but sometimes coated with a material to enhance phosphorescence.

Do Fluorites Receive Artificial Enhancements?

Heating to 100-150° C can lighten dark-colored fluorites, but higher temperatures risk removing all color. On the other hand, radiation treatment can turn colorless and pale green material darker blue, green, or purple.

Decorative objects might receive coating, dyeing, and plastic impregnation treatments.

Fluorite Sources

Fluorites occur in many localities worldwide.

The most well-known sources of gem-quality material include the following:

• Ontario, Canada: banded, violet material in calcite.
• Colombia: green.
• Huanzala, Peru: pink crystals.
• Chamonix, Switzerland; octahedral pink crystals, on quartz, very rare.
• United Kingdom: Cornwall; Cumberland; Derbyshire.
• United States: Colorado; Illinois (occurs in many colors, best known, especially violet material from Rosiclare); Michigan; Missouri (purple, blue, yellow, brown, colorless); Westmoreland, New Hampshire (bright green fluorite in crystals up to 8 inches across); New Mexico.
• Argentina; Austria; China; Czech Republic; France; Germany; Italy; Korea; Morocco; Myanmar; Namibia; Pakistan; Russia; Slovakia; South Africa.

How Large Can Fluorite Gemstones Get?

Since suitable rough from a wide range of localities is available, fluorite crystals can be very large. However, large stones totally free of internal flaws are extremely rare. Thus, cut fluorites suitable for jewelry use are usually small.

• Smithsonian Institution (Washington, DC): 729 (green, Colombia); 492, 354 (pink, Korea); 348 (pale blue, Korea); 263, 234 (light brown, Africa); 118 (purple, England); 354 (pale yellow, Illinois); 229, 124.5 (green, New Hampshire); 117 (green, Africa); 111.2 (violet, Illinois); 118.5, 85.4 (blue, Illinois); 32.7 (colorless, Illinois); 13 (pink, Switzerland).
• Devonian Group (Calgary, Alberta, Canada): 68 (deep blue, Namibia), 23.7 (pink, Africa); 72.4 (green).
• Harvard University: 180 (green, New Hampshire).
• Los Angeles County Museum: 1031 (yellow, triangle, Cave-in-Rock, Illinois, world's largest yellow fluorite); 100 (chrome fluorite, Colombia); 30 (chrome fluorite, Azusa Canyon, Los Angeles County, California).
• Private Collection: 100+ (pink, South Africa); 203.5 (yellow, Illinois); 17.92 (brown, Michigan); 3969 (Kashmir-sapphire blue, Illinois).

Is Fluorite Hazardous?

Fluorites contain fluorine (F) as part of their chemical makeup (CaF₂). As a gas, fluorine is very toxic. However, fluorites are inert. Wearing or holding fluorite gems or jewelry will pose no health risks. The lapidary processes used to cut fluorites won't create fluorine gas. (Of course, gem cutters should take basic precautions when working with any gem material).

There are health risks associated with long-term exposure to massive amounts of fluorite in or near mining environments. However, normal gem cutting and handling just won't result in exposure on that scale.

How to Take Care of Your Fluorite Jewelry

Due to its cleavage, brittleness, and low hardness, fluorite is too fragile for most jewelry use. Ring use isn't recommended. However, protective settings, occasional wear, and use in pendants and earrings can let you show off these beautiful gems. Some specimens may fade with prolonged exposure to light, so store any fluorite jewelry out of the light. In addition, store them separately from other harder gemstones to prevent contact scratches.

Since fluorites are slightly soluble in water, never submerge them. Clean them only with a warm damp cloth, detergent, and soft brush and never use mechanical cleaning systems. For more cleaning recommendations, consult our gemstone jewelry cleaning guide.

Joel E. Arem, Ph.D., FGA

Dr. Joel E. Arem has more than 60 years of experience in the world of gems and minerals. After obtaining his Ph.D. in Mineralogy from Harvard University, he has published numerous books that are still among the most widely used references and guidebooks on crystals, gems and minerals in the world.

Co-founder and President of numerous organizations, Dr. Arem has enjoyed a lifelong career in mineralogy and gemology. He has been a Smithsonian scientist and Curator, a consultant to many well-known companies and institutions, and a prolific author and speaker. Although his main activities have been as a gem cutter and dealer, his focus has always been education. joelarem.com

View All Articles

International Gem Society

View All Articles