The facts
What smithsonite actually is
The species behind smithsonite is smithsonite, ZnCO₃; it forms in the trigonal system.
Cu²⁺ for the blue-green Kelly Mine material, Co²⁺ for pink, Cd for yellow, Fe for brown 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 1.621–1.849 and a specific gravity of about 4.30–4.45, with perfect rhombohedral cleavage.
Where smithsonite comes from
Commercial material comes from Kelly Mine, Magdalena, New Mexico, USA, Tsumeb, Namibia, Choix, Sinaloa, Mexico (pink) and Broken Hill, Zambia.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How smithsonite is treated
Untreated. The botryoidal blue-green Kelly material is the classic; some cabochons are stabilised. High RI and a very high birefringence give it a distinctive silky glow that separates it from chrysocolla and turquoise.
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 smithsonite is confused with
Watch for Chrysocolla, Turquoise, Hemimorphite and Prehnite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.621–1.849 and specific gravity 4.30–4.45 settle most of it in a minute, and magnification settles the rest.
What smithsonite is used for
The trades that buy smithsonite are mineral collecting, jewellery 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 specimen, by the carat or by the block.
Durability and care
Hardness 4–4.5; cleavage perfect rhombohedral. 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 smithsonite costs
Expect roughly Cabochons $20–$150; fine Kelly or Tsumeb specimens $200–$8,000, 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 smithsonite treated, and how?
Untreated. The botryoidal blue-green Kelly material is the classic; some cabochons are stabilised. High RI and a very high birefringence give it a distinctive silky glow that separates it from chrysocolla and turquoise.
Where does smithsonite come from?
Kelly Mine, Magdalena, New Mexico, USA, Tsumeb, Namibia, Choix, Sinaloa, Mexico (pink) and Broken Hill, Zambia. Origin affects price, so we name the locality rather than the country on every quote.
Is smithsonite hard enough to wear every day?
Not really. At 4–4.5 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 smithsonite cost?
Indicatively Cabochons $20–$150; fine Kelly or Tsumeb specimens $200–$8,000. 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 smithsonite confused with?
Most often Chrysocolla, Turquoise, Hemimorphite and Prehnite. A refractive index of 1.621–1.849 and a specific gravity near 4.30–4.45 separate it quickly.
What is smithsonite used for besides jewellery?
mineral collecting and carving and sculpture. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for smithsonite?
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 smithsonite