The facts
What thulite actually is
Mineralogically, thulite is zoisite — Ca₂Al₃(SiO₄)₃(OH) with Mn, crystallising in the orthorhombic (massive aggregate) system.
The colour is caused by mn³⁺ substituting in the structure, with an absorption band near 530 nm. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.690–1.700 (spot ~1.70), and the specific gravity sits near 3.10–3.40; cleavage is perfect {010}, not seen in the massive aggregate.
Where thulite comes from
The recognised sources are Leksvik and Sauland, Norway, Lom, Norway, Mitchell County, North Carolina, USA and Western Australia.
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 thulite is treated
Generally untreated, and the frequently repeated claim that thulite is dyed is not supported by the sources consulted. The real treatment issue is heat behaviour: ordinary heating destroys the pink by reducing Mn³⁺ to colourless Mn²⁺, leaving a pale lavender or bluish stone, and the pink survives only under oxidising conditions. Ask about oxidising heat, not dye.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What thulite is confused with
The usual confusions are Rhodonite, Rhodochrosite, Pink dyed marble, Bustamite and Unakite.
The separation is rarely a matter of opinion: refractive index 1.690–1.700 (spot ~1.70) and specific gravity 3.10–3.40 settle most of it in a minute, and magnification settles the rest.
What thulite is used for
Thulite is bought by carving and sculpture, decorative objects, architecture and interiors, jewellery and mineral collecting — 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 block, by the piece or by the square metre.
Durability and care
Hardness 6–6.5; cleavage perfect {010}, not seen in the massive aggregate. That combination decides what it can safely be set into.
Hardness is not the whole story. Perfect cleavage means the stone can split cleanly if struck along the wrong plane, whatever its Mohs number, so a protective setting matters more here than the hardness suggests.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What thulite costs
Indicative pricing for thulite is $0.50–10/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 thulite treated, and how?
Generally untreated, and the frequently repeated claim that thulite is dyed is not supported by the sources consulted. The real treatment issue is heat behaviour: ordinary heating destroys the pink by reducing Mn³⁺ to colourless Mn²⁺, leaving a pale lavender or bluish stone, and the pink survives only under oxidising conditions. Ask about oxidising heat, not dye.
Where does thulite come from?
Leksvik and Sauland, Norway, Lom, Norway, Mitchell County, North Carolina, USA and Western Australia. Origin affects price, so we name the locality rather than the country on every quote.
Is thulite hard enough to wear every day?
With care. It is 6–6.5 on the Mohs scale, which is hard enough, but perfect {010}, not seen in the massive aggregate cleavage means it can split if struck at the wrong angle. Use a protective setting and avoid ultrasonic cleaning.
How much does thulite cost?
Indicatively $0.50–10/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 thulite confused with?
Most often Rhodonite, Rhodochrosite, Pink dyed marble, Bustamite and Unakite. A refractive index of 1.690–1.700 (spot ~1.70) and a specific gravity near 3.10–3.40 separate it quickly.
What is thulite used for besides jewellery?
carving and sculpture, decorative objects, architecture and interiors and mineral collecting. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for thulite?
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 thulite