Arizona: Sleeping Beauty Turquoise and the Peridot Capital of the World

Arizona gave the world two of its most recognisable gemstones, and their stories run in opposite directions. Sleeping Beauty turquoise, from a mine near Globe, is famous for a clean robin's-egg blue with no matrix at all — and it stopped coming out of the ground in 2012, when the mine turned its full attention to copper. Peridot, meanwhile, still pours out of a basalt-capped mesa on the San Carlos Apache Reservation, which is commonly credited with producing the large majority of the world's supply — much of it dug by hand, by Apache families, on land where only tribal members may mine. One gem is now a lesson in scarcity; the other is a lesson in stewardship. And remarkably, both come from the same stretch of copper country in Gila County, east of Phoenix.

The mountain that looked like a sleeping woman

The Sleeping Beauty mine sits near the old copper town of Globe, and it takes its name from the mountain above it, which from a distance is said to resemble a woman lying on her back, arms folded. Like most turquoise in the American Southwest, the stone here was a by-product of copper — turquoise forms where water carries copper through weathered rock, so wherever miners chased copper ore, blue veins tended to turn up alongside it.

What made Sleeping Beauty different was the character of the blue. Most turquoise carries a matrix — the dark spiderwebbing of its host rock, which many collectors love. Sleeping Beauty produced something rarer: solid, even, sky-blue stone with little or no matrix at all, the colour usually described as robin's-egg blue. That cleanness carried its reputation far beyond the Southwest. Native American silversmiths prized it, and it became a favourite of fine jewellery houses in Europe and Asia, where an unblemished, uniform blue suits calibrated settings in a way mottled stone cannot.

2012: the year the blue stopped

In August 2012, the Sleeping Beauty operation stopped mining turquoise altogether and turned exclusively to copper — reportedly a matter of economics and regulation, since copper simply paid better than the blue stone ever could. No dramatic announcement, no farewell. The turquoise just stopped.

What followed is one of the more honest scarcity stories in the gem world. Nothing about the stone itself changed; there is simply no new supply, and there may never be again. Dealers who had bought rough by the barrel in earlier decades found themselves sitting on stockpiles that appreciated year after year, and the price of genuine, natural Sleeping Beauty has climbed markedly since the closure. Scarcity has always written the gem trade's best legends — it is the same force behind the most famous diamonds in history — but here it arrived quietly, in a working copper pit, within living memory.

A word of honest caution: that price climb has pulled a wave of imitations into the market. A great deal of stone sold under the Sleeping Beauty name is stabilised, dyed, or not from the mine at all. If provenance matters to you, buy from dealers who can trace their rough to pre-closure stock, and treat bargain-priced "Sleeping Beauty" with healthy suspicion.

Kingman: the other great Arizona blue

Sleeping Beauty is not Arizona's only storied turquoise. In the Cerbat Mountains near Kingman, in the state's northwest corner, lies one of the oldest and largest turquoise sources in North America. Archaeological finds — including caches of ancient stone hammers uncovered in old trenches when modern work began — suggest Indigenous miners were digging these deposits as far back as around AD 600, long before commercial mining took hold in the late nineteenth century.

Since 1962 the Kingman turquoise concession has been worked by the Colbaugh family, and it is often described as the last major commercially producing turquoise mine in the United States. Where Sleeping Beauty was prized for its absence of matrix, Kingman is loved for the opposite reason: deep blues laced with black and silvery webbing, each stone a one-off map. Between the two names — one silenced, one still working — Arizona has a fair claim to being America's turquoise heartland.

Peridot Mesa: the hill that supplies the world

Drive east from Globe and you cross onto the San Carlos Apache Reservation, home to a low, basalt-capped rise called Peridot Mesa. It looks unremarkable. It is, by many accounts, the single largest source of gem peridot on Earth — commonly credited with supplying the large majority of the world's output, particularly the bright green stones you see in everyday fine jewellery.

What makes Peridot Mesa genuinely special is how the mining is done. Only enrolled members of the San Carlos Apache Tribe may mine there, and most of the work is done by hand — hammers, chisels, pry bars, patience — with families working individual claims, often across generations. There is no vast open pit, no fleet of haul trucks; the gem gets from the ground into the trade through small-scale, human-scale labour, with mining rights held by the community whose land it is. Visitors cannot simply turn up and dig, which sets it apart from a place like Crater of Diamonds in Arkansas, where the public fossicks freely. Here, the gem belongs to the Apache first, and the world buys what they choose to sell.

There is lovely timing in publishing this in August, because peridot is the August birthstone — one of the few birthstones where a single American hillside genuinely dominates the world's supply of it.

Born in fire — and sometimes in space

Peridot is gem-quality olivine, and it is one of the very few gems formed not in the Earth's crust but in the mantle, far below it. At Peridot Mesa, ancient basalt lava flows carried chunks of mantle rock — olivine-rich nodules — up to the surface and cooled around them, sealing green crystals inside dark volcanic stone. Apache miners today are essentially cracking open frozen lava to retrieve cargo from the deep Earth. Diamond is the only other well-known gem with that mantle pedigree, rushed to the surface by eruptions of its own — a journey we describe in our piece on how diamonds form and how they are grown.

And peridot goes one better: it is the only gemstone routinely found beyond Earth. Pallasite meteorites — remnants from the birth of the solar system some 4.5 billion years ago — carry olivine crystals in a nickel-iron matrix, and a few contain true gem-quality peridot. GIA has examined faceted pallasitic peridot, though the stones are usually tiny, typically under half a carat. An August birthday, in other words, comes with a birthstone that is older than the planet it is mined on.

Two gems, one honest lesson

Set side by side, Arizona's two gems make a quiet argument about value. Sleeping Beauty shows what happens when supply simply ends: the stone becomes a memory you can wear, and its price follows its rarity. Peridot Mesa shows the opposite — abundance handled with care, by the people whose land it is, at a pace the hill can sustain. Neither story needed embellishment; the truth of each is what makes it good.

That is roughly how we think about diamonds at Signora. We work only with lab-grown stones, made to order in Surat, India, each one IGI-certified with its report number laser-inscribed on the girdle — because we would rather tell you plainly where a gem comes from than lean on mystery. If Arizona's greens and blues have put you in the mood for a stone with a documented story of its own, our engagement ring collection is a good place to wander — every stone there arrives with its paperwork, not its legend.