The facts
What rosasite actually is
The species behind rosasite is rosasite, (Cu,Zn)₂(CO₃)(OH)₂; it forms in the monoclinic system.
Cu²⁺ with Zn substitution, giving blue-green to green botryoidal crusts 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 1.672–1.830 and a specific gravity of about 4.0–4.2, with perfect {010} and {100} cleavage.
Where rosasite comes from
Commercial material comes from Rosas Mine, Sulcis, Sardinia, Italy (type locality), Ojuela Mine, Mapimí, Durango, Mexico and Tsumeb, Namibia.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How rosasite is treated
Untreated. The velvety spherules from Mapimí are the classic material and are routinely confused with aurichalcite; rosasite is distinctly harder and has a botryoidal rather than acicular habit.
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 rosasite is confused with
Watch for Aurichalcite, Malachite, Chrysocolla and Smithsonite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.672–1.830 and specific gravity 4.0–4.2 settle most of it in a minute, and magnification settles the rest.
What rosasite is used for
The trades that buy rosasite 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
Rosasite is 4 on the Mohs scale, with perfect {010} and {100} 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 rosasite costs
Expect roughly Specimens $30–$800, 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 rosasite treated, and how?
Untreated. The velvety spherules from Mapimí are the classic material and are routinely confused with aurichalcite; rosasite is distinctly harder and has a botryoidal rather than acicular habit.
Where does rosasite come from?
Rosas Mine, Sulcis, Sardinia, Italy (type locality), Ojuela Mine, Mapimí, Durango, Mexico and Tsumeb, Namibia. Origin affects price, so we name the locality rather than the country on every quote.
Is rosasite hard enough to wear every day?
Not really. At 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 rosasite cost?
Indicatively Specimens $30–$800. 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 rosasite confused with?
Most often Aurichalcite, Malachite, Chrysocolla and Smithsonite. A refractive index of 1.672–1.830 and a specific gravity near 4.0–4.2 separate it quickly.
Related stones
Looking for rosasite?
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 rosasite