The facts
What villiaumite actually is
Villiaumite is classified as villiaumite, with the composition NaF. It crystallises in the cubic system.
Colour comes from colour centres from natural irradiation giving carmine to orange-red; heating bleaches it, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.327. Specific gravity around 2.79. Cleavage: perfect cubic. Those three numbers separate it from most of what imitates it.
Where villiaumite comes from
Villiaumite is produced at Mont Saint-Hilaire, Quebec, Canada, Lovozero and Khibiny massifs, Kola Peninsula, Russia and Poços de Caldas, Minas Gerais, Brazil.
The locality is part of the description, not a footnote — two stones of the same weight from two of these places are not the same stone.
How villiaumite is treated
Untreated. Water-soluble and genuinely toxic — sodium fluoride — so specimens must be kept dry, sealed and never handled with damp hands or taste-tested. Has the lowest refractive index of any mineral in common collections.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What villiaumite is confused with
In the trade villiaumite is most often mistaken for, or substituted by, Fluorite, Halite, Realgar or Erythrite.
The separation is rarely a matter of opinion: refractive index 1.327 and specific gravity 2.79 settle most of it in a minute, and magnification settles the rest.
What villiaumite is used for
Demand for villiaumite comes from mineral collecting, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the specimen.
Durability and care
Hardness 2–2.5; cleavage perfect cubic. That combination decides what it can safely be set into.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What villiaumite costs
As a guide, villiaumite trades around Specimens $30–$400.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is villiaumite treated, and how?
Untreated. Water-soluble and genuinely toxic — sodium fluoride — so specimens must be kept dry, sealed and never handled with damp hands or taste-tested. Has the lowest refractive index of any mineral in common collections.
Where does villiaumite come from?
Mont Saint-Hilaire, Quebec, Canada, Lovozero and Khibiny massifs, Kola Peninsula, Russia and Poços de Caldas, Minas Gerais, Brazil. Origin affects price, so we name the locality rather than the country on every quote.
Is villiaumite hard enough to wear every day?
Not really. At 2–2.5 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does villiaumite cost?
Indicatively Specimens $30–$400. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is villiaumite confused with?
Most often Fluorite, Halite, Realgar and Erythrite. A refractive index of 1.327 and a specific gravity near 2.79 separate it quickly.
Related stones
Looking for villiaumite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about villiaumite