Turquoise
Turquoise is the stone people think they know. It is also the stone most often sold as something it isn't. This page is the version we'd give you across the bench.
What is turquoise, really?
A hydrated copper aluminium phosphate that forms in arid country where groundwater percolates through copper deposits. Copper gives the blue; iron pushes it green. The dark webbing — the matrix — is the host rock it grew inside, which is why no two stones repeat.
It is soft. Mohs 5 to 6, softer than window glass, and porous on top of that. This single fact explains almost everything else about how turquoise is sold.
Why is almost all turquoise treated?
Untreated turquoise hard enough to cut and set is a small fraction of what comes out of the ground. The rest is chalky, and will absorb skin oil, soap and perfume until it turns green and dull. So the trade stabilises it: resin is forced into the pores under pressure, hardening the stone and locking the colour.
Stabilised turquoise is still turquoise. It is not a fake. But a seller who never mentions treatment is either uninformed or hoping you are — and the honest answer to "is this stabilised?" is almost always yes.
Two things worth naming separately. Reconstituted turquoise is powder and dust bound back together with resin. Block or imitation turquoise contains no turquoise at all; it is dyed howlite, magnesite or plastic. Dyed howlite is convincing enough that it accounts for a lot of what is sold as turquoise online. We sell howlite as howlite.
What happened to Sleeping Beauty turquoise?
The Sleeping Beauty mine near Globe, Arizona produced clean, even, matrix-free blue — the turquoise most people picture. It stopped producing turquoise in 2012, when the operation turned to copper. Within months, rough was reportedly trading at three to five times its previous price, and everything on the market since has come out of stock mined before then.
So treat the name carefully. Genuine Sleeping Beauty material exists, and it is finite and expensive. A great deal of what carries the name is not it.
Is purple turquoise real?
Purple turquoise does not occur in nature. Mohave turquoise starts as real Kingman turquoise from Arizona, then is stabilised and infused with other minerals under heat and pressure to give the bronze-web matrix and the colour. It is a genuine, deliberate, branded material with real turquoise in it — and it is a treated composite, not a natural purple stone. Anyone selling it as the latter is telling you a story.
How do you care for turquoise?
Keep it away from perfume, hairspray, chlorine and hot water. Put jewellery on after scent, not before. Clean with a dry or barely damp cloth — never an ultrasonic cleaner, which will drive water into the stone and can lift the polish. Stored beside harder stones it will scratch, so give it its own pouch.