The facts
What halloysite actually is
Mineralogically, halloysite is a kaolin-group clay mineral that grows as hollow nanotubes rather than plates, which is the basis of its speciality value — Al2Si2O5(OH)4.2H2O (the hydrated form) or Al2Si2O5(OH)4, crystallising in the aggregate (monoclinic, tubular morphology) system.
The colour is caused by white; brightness matters for the ceramic and filler grades. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.53-1.56, and the specific gravity sits near 2.00-2.65; cleavage is none in the tubes.
Where halloysite comes from
The recognised sources are Dragon Mine, Tintic district, Juab County, Utah, USA, Matauri Bay and Te Puna, Northland, New Zealand - the classic high-purity porcelain-grade deposit, Turkiye and Poland and Hunan and Guizhou, China.
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 halloysite is treated
Refined and size-classified; the nanotube grades are purified and sometimes surface-functionalised. Uses split sharply: bulk halloysite goes into fine bone china and porcelain (Matauri Bay clay is the standard for premium tableware), while purified halloysite nanotubes are a genuine speciality material for controlled-release carriers, polymer reinforcement, flame retardants and catalysis. It is one of the few natural minerals with a real nanotechnology market. Not hazardous in bulk, but as with all clays respirable dust needs control.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What halloysite is confused with
The usual confusions are Kaolin (platy, not tubular), Carbon nanotubes (the synthetic competitor for nanotube applications) and Ball clay.
The separation is rarely a matter of opinion: refractive index 1.53-1.56 and specific gravity 2.00-2.65 settle most of it in a minute, and magnification settles the rest.
What halloysite is used for
Halloysite is bought by heavy industry, filtration and cosmetics — 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 tonne.
Durability and care
Halloysite is 1-2 on the Mohs scale, with none in the tubes 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 halloysite costs
Indicative pricing for halloysite is $200-800 per tonne for ceramic grades; purified nanotube grades $50-500 per kilogram.
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 halloysite treated, and how?
Refined and size-classified; the nanotube grades are purified and sometimes surface-functionalised. Uses split sharply: bulk halloysite goes into fine bone china and porcelain (Matauri Bay clay is the standard for premium tableware), while purified halloysite nanotubes are a genuine speciality material for controlled-release carriers, polymer reinforcement, flame retardants and catalysis. It is one of the few natural minerals with a real nanotechnology market. Not hazardous in bulk, but as with all clays respirable dust needs control.
Where does halloysite come from?
Dragon Mine, Tintic district, Juab County, Utah, USA, Matauri Bay and Te Puna, Northland, New Zealand - the classic high-purity porcelain-grade deposit, Turkiye and Poland and Hunan and Guizhou, China. Origin affects price, so we name the locality rather than the country on every quote.
Is halloysite hard enough to wear every day?
Not really. At 1-2 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 halloysite cost?
Indicatively $200-800 per tonne for ceramic grades; purified nanotube grades $50-500 per kilogram. 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 halloysite confused with?
Most often Kaolin (platy, not tubular), Carbon nanotubes (the synthetic competitor for nanotube applications) and Ball clay. A refractive index of 1.53-1.56 and a specific gravity near 2.00-2.65 separate it quickly.
What is halloysite used for besides jewellery?
heavy industry, filtration and cosmetics. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for halloysite?
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 halloysite