The facts
What serpentinite actually is
Serpentinite is classified as a metamorphic rock of serpentine-group minerals formed by hydration of ultramafic rock, with the composition Antigorite, lizardite and chrysotile Mg3Si2O5(OH)4, with magnetite, chromite and calcite. It crystallises in the aggregate (monoclinic serpentine) system.
Colour comes from fe2+ and Ni give the greens; the mottling reflects the original ultramafic texture, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.55-1.57. Specific gravity around 2.44-2.80. Cleavage: none as a rock. Those three numbers separate it from most of what imitates it.
Where serpentinite comes from
Serpentinite is produced at Connemara, County Galway, Ireland (Connemara marble), Lizard Peninsula, Cornwall, England, Val Malenco and Valtellina, Italy, Zhenping and Xiuyan, Liaoning Province, China ('Xiuyan jade') and Rhode Island, USA (the bowenite type locality).
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 serpentinite is treated
Frequently waxed, oiled and dyed; sold constantly as 'new jade', 'olive jade' and 'Korea jade'. Bowenite is the hard antigorite variety and is the only serpentine with real jade-like durability. HEALTH: chrysotile serpentine is a form of asbestos, and some serpentinites contain fibrous chrysotile or tremolite - dry cutting is a genuine hazard and should not be done. Not CITES.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What serpentinite is confused with
In the trade serpentinite is most often mistaken for, or substituted by, Jade (nephrite and jadeite) - the constant misrepresentation, Soapstone, Verdite, Dyed marble or Green glass.
The separation is rarely a matter of opinion: refractive index 1.55-1.57 and specific gravity 2.44-2.80 settle most of it in a minute, and magnification settles the rest.
What serpentinite is used for
Demand for serpentinite comes from carving and sculpture, architecture and interiors, decorative objects and jewellery, 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 square metre or by the piece.
Durability and care
Serpentinite is 2.5-5.5 (bowenite, the antigorite-rich gem variety, reaches 5-5.5) on the Mohs scale, with none as a rock 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 serpentinite costs
As a guide, serpentinite trades around $1-10 per kilogram rough; carvings $10-500; Connemara marble jewellery $20-200.
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 serpentinite treated, and how?
Frequently waxed, oiled and dyed; sold constantly as 'new jade', 'olive jade' and 'Korea jade'. Bowenite is the hard antigorite variety and is the only serpentine with real jade-like durability. HEALTH: chrysotile serpentine is a form of asbestos, and some serpentinites contain fibrous chrysotile or tremolite - dry cutting is a genuine hazard and should not be done. Not CITES.
Where does serpentinite come from?
Connemara, County Galway, Ireland (Connemara marble), Lizard Peninsula, Cornwall, England, Val Malenco and Valtellina, Italy, Zhenping and Xiuyan, Liaoning Province, China ('Xiuyan jade') and Rhode Island, USA (the bowenite type locality). Origin affects price, so we name the locality rather than the country on every quote.
Is serpentinite hard enough to wear every day?
Not really. At 2.5-5.5 (bowenite, the antigorite-rich gem variety, reaches 5-5.5) 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 serpentinite cost?
Indicatively $1-10 per kilogram rough; carvings $10-500; Connemara marble jewellery $20-200. 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 serpentinite confused with?
Most often Jade (nephrite and jadeite) - the constant misrepresentation, Soapstone, Verdite, Dyed marble and Green glass. A refractive index of 1.55-1.57 and a specific gravity near 2.44-2.80 separate it quickly.
What is serpentinite used for besides jewellery?
carving and sculpture, architecture and interiors and decorative objects. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for serpentinite?
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 serpentinite