The facts
What pyrite actually is
Pyrite is classified as iron sulphide, with the composition FeS₂. It crystallises in the cubic system.
Colour comes from metallic, which is also what a laboratory looks at when it is asked whether a colour is natural.
Specific gravity around 4.9–5.2. Cleavage: indistinct. Those three numbers separate it from most of what imitates it.
Where pyrite comes from
Pyrite is produced at Navajún, Spain, Peru, Italy and China.
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.
Is pyrite treated?
None. It can decompose over time — "pyrite disease".
That makes disclosure simple: there is nothing to declare. It also means a seller offering a "treated" version of this material is offering something else.
What pyrite is confused with
In the trade pyrite is most often mistaken for, or substituted by, Marcasite, Chalcopyrite or Gold.
Because the material is opaque, refractive index is no help. Specific gravity around 4.9–5.2, hardness of 6–6.5, streak and magnification do the work instead.
What pyrite is used for
Demand for pyrite comes from mineral collecting, 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 specimen, by the piece or by the carat.
Durability and care
Hardness 6–6.5; cleavage indistinct. That combination decides what it can safely be set into.
With no cleavage plane to worry about, the practical limit is abrasion rather than breakage, and it takes daily wear well.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What pyrite costs
As a guide, pyrite trades around $0.05–2/g.
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 pyrite treated?
None. It can decompose over time — "pyrite disease".
Where does pyrite come from?
Navajún, Spain, Peru, Italy and China. Origin affects price, so we name the locality rather than the country on every quote.
Is pyrite hard enough to wear every day?
Yes. At 6–6.5 on the Mohs scale with no cleavage plane, it handles daily wear well. The practical limit is gradual abrasion rather than chipping.
How much does pyrite cost?
Indicatively $0.05–2/g. 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 pyrite confused with?
Most often Marcasite, Chalcopyrite and Gold. Since the material is opaque, separation relies on specific gravity near 4.9–5.2, hardness and magnification.
What is pyrite used for besides jewellery?
mineral collecting and decorative objects. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for pyrite?
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 pyrite