The facts
What cameo Shell actually is
Cameo Shell is classified as thick helmet-shell wall with contrasting colour layers, carved in relief, with the composition Aragonite / calcite CaCO3 with conchiolin. It crystallises in the aggregate system.
Colour comes from natural pigmented layers in the shell wall; the carver exploits the white outer over coloured inner, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.53-1.68. Specific gravity around 2.65-2.85. Cleavage: none. Those three numbers separate it from most of what imitates it.
Where cameo Shell comes from
Cameo Shell is produced at Cassis madagascariensis (sardonyx shell), Caribbean and Florida waters, Cypraecassis rufa (cornelian / bullmouth), East African and Indo-Pacific coasts and Torre del Greco, Italy - the historic carving centre, not a source.
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 cameo Shell is treated
Not CITES-listed, though Cassis species are regulated locally and Florida restricts helmet-shell collection. Dye is used to deepen the background on cheaper cameos. The commercial problem is moulded resin cameos and computer-carved shell sold as hand-carved Italian work; hand carving shows tool marks and asymmetry under 10x.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What cameo Shell is confused with
In the trade cameo Shell is most often mistaken for, or substituted by, Moulded resin and plastic cameos, Glass cameos, Carved agate and onyx (harder, more valuable) or Machine-carved shell.
The separation is rarely a matter of opinion: refractive index 1.53-1.68 and specific gravity 2.65-2.85 settle most of it in a minute, and magnification settles the rest.
What cameo Shell is used for
Demand for cameo Shell comes from jewellery, carving and sculpture 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 carat, by the block or by the specimen.
Durability and care
Cameo Shell is 3-4 on the Mohs scale, with none 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 cameo Shell costs
As a guide, cameo Shell trades around $30-400 for ordinary hand-carved shell cameos; signed Torre del Greco master work $1,000-15,000.
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 cameo Shell treated, and how?
Not CITES-listed, though Cassis species are regulated locally and Florida restricts helmet-shell collection. Dye is used to deepen the background on cheaper cameos. The commercial problem is moulded resin cameos and computer-carved shell sold as hand-carved Italian work; hand carving shows tool marks and asymmetry under 10x.
Where does cameo Shell come from?
Cassis madagascariensis (sardonyx shell), Caribbean and Florida waters, Cypraecassis rufa (cornelian / bullmouth), East African and Indo-Pacific coasts and Torre del Greco, Italy - the historic carving centre, not a source. Origin affects price, so we name the locality rather than the country on every quote.
Is cameo Shell hard enough to wear every day?
Not really. At 3-4 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 cameo Shell cost?
Indicatively $30-400 for ordinary hand-carved shell cameos; signed Torre del Greco master work $1,000-15,000. 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 cameo Shell confused with?
Most often Moulded resin and plastic cameos, Glass cameos, Carved agate and onyx (harder, more valuable) and Machine-carved shell. A refractive index of 1.53-1.68 and a specific gravity near 2.65-2.85 separate it quickly.
What is cameo Shell used for besides jewellery?
carving and sculpture and mineral collecting. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for cameo shell?
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 cameo shell