The combination of large sizes, beautiful colours, plentiful supply and value for money makes fluorite a very tempting stone to use in jewelry. But beware: this is a gemstone that’s fraught with problems and one that needs to be used wisely.
Fluorite’s name derives from the Latin for “to flow”; it melts more easily than other minerals and was once used as a flux. It comes in a variety of pretty transparent to translucent colours: bright golden yellow, bluish green, rose-pink, blue, green, purple and colourless. The stone has a glassy, vitreous lustre and takes a high polish.
Treatments and imitations
- Fluorite is often irradiated to deepen the colour, and pale stones are sometimes heated in oil for the same purpose. The cleavage of fluorite means that it is rather fragile for use in jewelry, so it is often impregnated with a resin or polymer to strengthen the material and make it less likely to break along its cleavage planes during carving, cutting or polishing.
- Fluorite cabochons are sometimes capped with rock crystal (clear quartz) to prevent the stone from being scratched or damaged.
- Calcium fluoride is fluorite simulated in a laboratory. Doping synthetic fluorite with different elements permits its manufacture in any colour.
Fluorite is an abundant, inexpensive material.
Working with fluorite
- Fluorite has traditionally been used as a material for carving decorative objects rather than as a gemstone for jewelry. Its softness makes it particularly suitable for carving cameos and intaglios.
- Fluorite has a conchoidal fracture and a perfect octahedral cleavage with four easy cleavage planes, which make it prone to breakage. The ease with which fluorite cleaves is remarkable. If it is heated the material will expand and split along the cleavage planes – there are reports of this happening in bright sunlight! Faceted fluorite is aimed at collectors only, as it is too fragile for jewelry. Beads and cabochons are less brittle and can be used, but they are not suitable for jewelry that might receive an impact, such as a ring or bracelet.
- When you purchase fluorite it is vital that you check its quality, especially if you are buying beads. Friction against other beads can easily cause chipping and scuffing and dull the polish. Fluorite should be stored on its own and rows of beads should be wrapped separately to protect them. When stringing fluorite beads, try to knot between each bead so that it doesn’t rub against its neighbour.
- A customer might return fluorite jewelry if a stone breaks or becomes damaged. Warn buyers that the material is delicate and inform them that the intense colours of fluorite can fade with extended exposure to sunlight.
Types of fluorite
A transparent emerald green fluorite from Namibia called African emerald is one of the most popular colours. It is also an interesting gemstone that often has many colours in a single crystal, with stripes, patches and spots that subtly merge together or stand out in sharp contrast to each other. Fluorite also occurs as an opaque mass.
Here is an example of the multiple colours that commonly appear side by side in fluorite.