The facts
What tortoiseshell actually is
The species behind tortoiseshell is keratinous carapace scutes of the hawksbill sea turtle Eretmochelys imbricata, Keratin protein; it forms in the amorphous system.
Melanin pigment granules in a translucent keratin ground, giving the mottled amber-and-brown pattern is responsible for the colour — and the chromophore, not the name, is what decides whether a colour is stable.
On the instruments it reads a refractive index of 1.55 and a specific gravity of about 1.26-1.35, with none; can be heat-welded, which is how large plates were historically made cleavage.
Where tortoiseshell comes from
Commercial material comes from Historic: Caribbean, Indonesia, the Philippines, and the Japanese bekko trade at Nagasaki and No legal current source.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How tortoiseshell is treated
CITES APPENDIX I - international commercial trade is banned outright, and this covers antique and worked material in most jurisdictions unless it is pre-Convention with documentation. The US ESA and EU rules are stricter still. Do not buy, sell or ship it internationally without specialist legal advice. Hawksbill remains critically endangered. Plastic imitations have been standard since the 1920s.
We state the treatment on every stone, including when the honest answer is that it cannot be determined. A treatment disclosed is a fact; a treatment discovered later is a refund.
What tortoiseshell is confused with
Watch for Cellulose nitrate and casein plastics (the standard imitation), Horn, stained, Modern acetate 'tortoiseshell' eyewear and Plastic — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.55 and specific gravity 1.26-1.35 settle most of it in a minute, and magnification settles the rest.
What tortoiseshell is used for
The trades that buy tortoiseshell are mineral collecting. They do not want the same thing, and they do not pay in the same unit.
We quote each application in the unit that trade actually buys in, by the specimen.
Durability and care
Hardness 2.5; cleavage none; can be heat-welded, which is how large plates were historically made. 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 tortoiseshell costs
Expect roughly No legitimate market; antique items trade only within domestic pre-Convention exemptions where those exist, depending on quality.
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 tortoiseshell treated, and how?
CITES APPENDIX I - international commercial trade is banned outright, and this covers antique and worked material in most jurisdictions unless it is pre-Convention with documentation. The US ESA and EU rules are stricter still. Do not buy, sell or ship it internationally without specialist legal advice. Hawksbill remains critically endangered. Plastic imitations have been standard since the 1920s.
Where does tortoiseshell come from?
Historic: Caribbean, Indonesia, the Philippines, and the Japanese bekko trade at Nagasaki and No legal current source. Origin affects price, so we name the locality rather than the country on every quote.
Is tortoiseshell hard enough to wear every day?
Not really. At 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 tortoiseshell cost?
Indicatively No legitimate market; antique items trade only within domestic pre-Convention exemptions where those exist. 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 tortoiseshell confused with?
Most often Cellulose nitrate and casein plastics (the standard imitation), Horn, stained, Modern acetate 'tortoiseshell' eyewear and Plastic. A refractive index of 1.55 and a specific gravity near 1.26-1.35 separate it quickly.
Related stones
Looking for tortoiseshell?
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 tortoiseshell