The facts
What legrandite actually is
Legrandite is classified as legrandite, with the composition Zn₂(AsO₄)(OH)·H₂O. It crystallises in the monoclinic system.
Colour comes from traces of Fe³⁺ giving the pure golden to canary yellow, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.675–1.740. Specific gravity around 3.98–4.04. Cleavage: imperfect {100}. Those three numbers separate it from most of what imitates it.
Where legrandite comes from
Legrandite is produced at Ojuela Mine, Mapimí, Durango, Mexico, Flor de Peña Mine, Nuevo León, Mexico and Tsumeb, Namibia.
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 legrandite is treated
Untreated. The 1970s Mapimí pockets — including the famous 'Aztec Sun' specimen — remain the source of virtually all fine legrandite, and prices reflect that closed supply. Arsenate; handle accordingly.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What legrandite is confused with
In the trade legrandite is most often mistaken for, or substituted by, Adamite, Wulfenite, Mimetite or Sulphur.
The separation is rarely a matter of opinion: refractive index 1.675–1.740 and specific gravity 3.98–4.04 settle most of it in a minute, and magnification settles the rest.
What legrandite is used for
Demand for legrandite comes from 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 specimen.
Durability and care
Hardness 4–5; cleavage imperfect {100}. 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 legrandite costs
As a guide, legrandite trades around Specimens $200–$50,000 for classic Mapimí sprays.
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 legrandite treated, and how?
Untreated. The 1970s Mapimí pockets — including the famous 'Aztec Sun' specimen — remain the source of virtually all fine legrandite, and prices reflect that closed supply. Arsenate; handle accordingly.
Where does legrandite come from?
Ojuela Mine, Mapimí, Durango, Mexico, Flor de Peña Mine, Nuevo León, Mexico and Tsumeb, Namibia. Origin affects price, so we name the locality rather than the country on every quote.
Is legrandite hard enough to wear every day?
Not really. At 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 legrandite cost?
Indicatively Specimens $200–$50,000 for classic Mapimí sprays. 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 legrandite confused with?
Most often Adamite, Wulfenite, Mimetite and Sulphur. A refractive index of 1.675–1.740 and a specific gravity near 3.98–4.04 separate it quickly.
Related stones
Looking for legrandite?
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 legrandite