The facts
What bastnäsite actually is
Mineralogically, bastnäsite is rare-earth fluorocarbonate — (Ce,La)(CO₃)F, crystallising in the hexagonal system.
The colour is caused by ce and La give honey-orange to reddish brown; very strong birefringence of about 0.100. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.717–1.818, and the specific gravity sits near 4.78–5.20; cleavage is distinct basal.
Where bastnäsite comes from
The recognised sources are Zagi Mountain, Khyber Pakhtunkhwa, Pakistan, Mountain Pass, San Bernardino County, California, USA and Trimouns, Ariège, France.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How bastnäsite is treated
Untreated. The world's main light rare-earth ore; Pakistani crystals give the few faceted stones on the market, all under a few carats.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What bastnäsite is confused with
The usual confusions are Parisite, Synchysite, Sphene and Zircon.
The separation is rarely a matter of opinion: refractive index 1.717–1.818 and specific gravity 4.78–5.20 settle most of it in a minute, and magnification settles the rest.
What bastnäsite is used for
Bastnäsite is bought by mineral collecting, heavy industry and technical and precision components — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen, by the tonne or by the piece.
Durability and care
Bastnäsite is 4–4.5 on the Mohs scale, with distinct basal cleavage.
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 bastnäsite costs
Indicative pricing for bastnäsite is Faceted stones 80–400 USD/ct.
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 bastnäsite treated, and how?
Untreated. The world's main light rare-earth ore; Pakistani crystals give the few faceted stones on the market, all under a few carats.
Where does bastnäsite come from?
Zagi Mountain, Khyber Pakhtunkhwa, Pakistan, Mountain Pass, San Bernardino County, California, USA and Trimouns, Ariège, France. Origin affects price, so we name the locality rather than the country on every quote.
Is bastnäsite hard enough to wear every day?
Not really. At 4–4.5 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 bastnäsite cost?
Indicatively Faceted stones 80–400 USD/ct. 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 bastnäsite confused with?
Most often Parisite, Synchysite, Sphene and Zircon. A refractive index of 1.717–1.818 and a specific gravity near 4.78–5.20 separate it quickly.
What is bastnäsite used for besides jewellery?
mineral collecting, heavy industry and technical and precision components. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for bastnäsite?
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 bastnäsite