The Stone Australia Almost Doesn't Have: Australian Turquoise

There is a stone in my tray this week that has no business being Australian. Turquoise.

Australia is opal country. We dig up most of the world's opal, and I have written to you about that already. Turquoise is a different story, and a much shorter one.

It is a copper mineral: a phosphate of copper and aluminium, if you want the chemistry. It forms slowly, in dry places, where water carrying dissolved copper has crept through cracks in the rock for a very long time and left a little of itself behind. That is why the great turquoise country is desert country. Arizona and Nevada have hills full of it. Persia, now Iran, has been mining it for thousands of years, and the sky-blue stone from Nishapur set the standard the rest of the world still measures itself against.

Australia has a handful of holes in the ground.

A few small workings near Bodalla, on the New South Wales south coast, were first dug in the 1890s and mostly forgotten since. There is a thin seam on a cattle station in the Northern Territory, somewhere between half an inch and six inches thick, that was worked in the 1970s and never really got going. A little in northern Victoria. In my older guide to Australian gemstones I gave turquoise two sentences, and that was about right. That is close to the whole list.

So when a piece of Australian turquoise turns up, I notice.

The blue is a little different from the American stone. It runs greener in places, where iron has crept into the crystal alongside the copper. Often there is a web of dark matrix running through it, the host rock the stone grew in, like a map of the ground it came out of. Some people polish that away. I think it is the most honest part of the stone. It tells you turquoise is not a gem that was cut from a clean crystal, but one that grew in the gaps of something else, and had to be found.

I set it plainly. Fine silver, nothing fussy around it. A stone this rare does not need help, and the warm, slightly greyed white of 999 silver sits better against that green-blue than anything brighter would. You can see how that works on the stones we love page, where the turquoise rings live alongside the opals.

Most of the turquoise in the world has an American passport. This one has only ever been here.

If you would like to see the difference for yourself, ask me at Paddington Markets on a Saturday morning. I will have an Arizona blue and an Australian one side by side on the tray, and once you have held both, you will not need me to tell you which is which.