The facts
What pyrophyllite actually is
Pyrophyllite is classified as pyrophyllite, with the composition Al₂Si₄O₁₀(OH)₂. It crystallises in the triclinic and monoclinic polytypes system.
Colour comes from white when pure; pale blue, green and yellow tints from trace Fe, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.534–1.601. Specific gravity around 2.65–2.90. Cleavage: perfect {001}; flexible laminae. Those three numbers separate it from most of what imitates it.
Where pyrophyllite comes from
Pyrophyllite is produced at Graves Mountain, Georgia, USA, Tres Cerritos, Mariposa County, California, USA, Ibitiara, Bahia, Brazil and Beryozovsk, Urals, Russia.
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 pyrophyllite is treated
Untreated, sometimes dyed. Very frequently confused with talc — the two are near-identical to the eye and hand. Sold as agalmatolite for Chinese and Korean figure carving, and used industrially in refractories and ceramics.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What pyrophyllite is confused with
In the trade pyrophyllite is most often mistaken for, or substituted by, Talc/soapstone, Serpentine, Alabaster or Dyed carving stone.
The separation is rarely a matter of opinion: refractive index 1.534–1.601 and specific gravity 2.65–2.90 settle most of it in a minute, and magnification settles the rest.
What pyrophyllite is used for
Demand for pyrophyllite comes from carving and sculpture, decorative objects, refractories, heavy industry and 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 block, by the piece or by the tonne.
Durability and care
Hardness 1–2; cleavage perfect {001}; flexible laminae. 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 pyrophyllite costs
As a guide, pyrophyllite trades around Nominal; carvings by the piece.
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 pyrophyllite treated, and how?
Untreated, sometimes dyed. Very frequently confused with talc — the two are near-identical to the eye and hand. Sold as agalmatolite for Chinese and Korean figure carving, and used industrially in refractories and ceramics.
Where does pyrophyllite come from?
Graves Mountain, Georgia, USA, Tres Cerritos, Mariposa County, California, USA, Ibitiara, Bahia, Brazil and Beryozovsk, Urals, Russia. Origin affects price, so we name the locality rather than the country on every quote.
Is pyrophyllite 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 pyrophyllite cost?
Indicatively Nominal; carvings by the piece. 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 pyrophyllite confused with?
Most often Talc/soapstone, Serpentine, Alabaster and Dyed carving stone. A refractive index of 1.534–1.601 and a specific gravity near 2.65–2.90 separate it quickly.
What is pyrophyllite used for besides jewellery?
carving and sculpture, decorative objects, refractories, heavy industry and mineral collecting. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for pyrophyllite?
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 pyrophyllite