The facts
What mother-of-Pearl actually is
The species behind mother-of-Pearl is the nacreous inner shell layer of pearl oysters and freshwater mussels, Aragonite CaCO3 platelets bound in conchiolin; it forms in the aggregate (orthorhombic aragonite) system.
Thin-film interference between aragonite platelets; pigment in the golden and black-lipped varieties 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 1.52-1.69 and a specific gravity of about 2.70-2.85, with none; parts along nacre layers cleavage.
Where mother-of-Pearl comes from
Commercial material comes from Pinctada maxima, Broome Australia and the Philippines (gold-lip and silver-lip), Pinctada margaritifera, French Polynesia (black-lip), Trochus niloticus, Indo-Pacific (button shell) and Hyriopsis / Unionid mussels, Mississippi basin, USA and China.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How mother-of-Pearl is treated
Bleaching and dyeing are common in the cheap end; 'black MOP' is often dyed. Trochus and pearl-oyster shell are not CITES-listed, but giant clam (Tridacnidae) and queen conch shell ARE Appendix II and are sometimes sold as generic 'mother of pearl' - check the species. The Convention on Migratory Species and national fisheries rules cap wild shell collection in Australia and Polynesia.
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 mother-of-Pearl is confused with
Watch for Dyed shell, Plastic and 'pearlescent' resin inlay and Abalone (paua) shell, which is more strongly iridescent — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.52-1.69 and specific gravity 2.70-2.85 settle most of it in a minute, and magnification settles the rest.
What mother-of-Pearl is used for
The trades that buy mother-of-Pearl are jewellery, decorative objects, architecture and interiors and carving and sculpture. 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 carat, by the piece or by the square metre.
Durability and care
Mother-of-Pearl is 2.5-4 on the Mohs scale, with none; parts along nacre layers 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 mother-of-Pearl costs
Expect roughly $0.50-20 per piece for blanks and inlay; large fine gold-lip shells $50-400 each, 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 mother-of-Pearl treated, and how?
Bleaching and dyeing are common in the cheap end; 'black MOP' is often dyed. Trochus and pearl-oyster shell are not CITES-listed, but giant clam (Tridacnidae) and queen conch shell ARE Appendix II and are sometimes sold as generic 'mother of pearl' - check the species. The Convention on Migratory Species and national fisheries rules cap wild shell collection in Australia and Polynesia.
Where does mother-of-Pearl come from?
Pinctada maxima, Broome Australia and the Philippines (gold-lip and silver-lip), Pinctada margaritifera, French Polynesia (black-lip), Trochus niloticus, Indo-Pacific (button shell) and Hyriopsis / Unionid mussels, Mississippi basin, USA and China. Origin affects price, so we name the locality rather than the country on every quote.
Is mother-of-Pearl hard enough to wear every day?
Not really. At 2.5-4 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 mother-of-Pearl cost?
Indicatively $0.50-20 per piece for blanks and inlay; large fine gold-lip shells $50-400 each. 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 mother-of-Pearl confused with?
Most often Dyed shell, Plastic and 'pearlescent' resin inlay and Abalone (paua) shell, which is more strongly iridescent. A refractive index of 1.52-1.69 and a specific gravity near 2.70-2.85 separate it quickly.
What is mother-of-Pearl used for besides jewellery?
decorative objects, architecture and interiors and carving and sculpture. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for mother-of-pearl?
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 mother-of-pearl