The facts
What faustite actually is
The species behind faustite is turquoise group, (Zn,Cu)Al₆(PO₄)₄(OH)₈·4H₂O; it forms in the triclinic system.
Zn-dominant with some Cu, giving yellow-green to apple green rather than turquoise blue 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 1.606–1.620 and a specific gravity of about 2.85–2.92, with not observed in massive material cleavage.
Where faustite comes from
Commercial material comes from Copper King Mine, Eureka County, Nevada, USA, Tsagaan Chuluut, Mongolia and Kerman Province, Iran.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How faustite is treated
Like turquoise, chalky faustite is very commonly stabilised with polymer and sometimes dyed; the green colour is nonetheless natural in good material. Full disclosure of stabilisation is uncommon in the bead trade.
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 faustite is confused with
Watch for Turquoise, Variscite, Chrysocolla and Dyed howlite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.606–1.620 and specific gravity 2.85–2.92 settle most of it in a minute, and magnification settles the rest.
What faustite is used for
The trades that buy faustite are jewellery and 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 carat or by the specimen.
Durability and care
Hardness 4.5–5; cleavage not observed in massive material. 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 faustite costs
Expect roughly Cabochons 20–200 USD depending on matrix and stability, 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 faustite treated, and how?
Like turquoise, chalky faustite is very commonly stabilised with polymer and sometimes dyed; the green colour is nonetheless natural in good material. Full disclosure of stabilisation is uncommon in the bead trade.
Where does faustite come from?
Copper King Mine, Eureka County, Nevada, USA, Tsagaan Chuluut, Mongolia and Kerman Province, Iran. Origin affects price, so we name the locality rather than the country on every quote.
Is faustite hard enough to wear every day?
Not really. At 4.5–5 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 faustite cost?
Indicatively Cabochons 20–200 USD depending on matrix and stability. 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 faustite confused with?
Most often Turquoise, Variscite, Chrysocolla and Dyed howlite. A refractive index of 1.606–1.620 and a specific gravity near 2.85–2.92 separate it quickly.
Related stones
Looking for faustite?
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 faustite