Oregon Sunstone: The Gem With Copper Inside

Oregon sunstone is the only gemstone in the world known to carry visible platelets of metallic copper inside it — millions of microscopic flakes of actual copper, suspended in the crystal like glitter frozen in glass. Tilt the stone and those platelets catch the light all at once, producing a soft metallic flash gem dealers call schiller. The same copper is responsible for the stone's remarkable colour range, from pale champagne through salmon and red to a rare deep green. Oregon made it the official state gemstone in 1987, and it remains one of the very few gems mined almost entirely on American soil.

What exactly is Oregon sunstone?

Strip away the romance and the mineralogy is humble: Oregon sunstone is feldspar — specifically a plagioclase feldspar of labradorite composition, a cousin of the most common mineral family in the Earth's crust. Sunstones of various kinds are found in India, Norway, Tanzania and elsewhere, but those stones get their sparkle from inclusions of minerals such as hematite. Oregon's is different. Here the inclusions are native copper: flat, highly reflective platelets aligned along the crystal's internal planes, which is why the schiller flashes as a single sheet of light rather than a random twinkle. Gemmological studies, including work published by GIA, confirm that Oregon is the only known source of gem-quality sunstone whose glow comes from copper.

The copper does double duty. Beyond the platelets you can see, copper dispersed invisibly through the crystal tints the stone itself — which is how one deposit can yield colourless, peach, red and green material, sometimes with two colours in a single crystal. If you enjoy understanding what actually makes a gem tick, our plain-English diamond and stone guide takes the same no-mystery approach to the stones we work with every day.

Born in a lava field

Every Oregon sunstone began as a crystal growing slowly inside molten basalt. Millions of years ago, lava flows spread across what is now the high desert of south-central Oregon, and as they cooled, feldspar crystals — some already seeded with copper — grew large within them. Geologists call these oversized crystals phenocrysts. Ages of weathering then did the miner's first shift of work: the basalt crumbled, and the tougher sunstone crystals washed free into the surface soil and gravel.

That is why the two great sunstone districts sit where they do. The best-known deposits lie in Lake County, in the sagebrush country of Rabbit Basin north of the tiny town of Plush. A second district sits in Harney County, where the Ponderosa mine works material associated with the Steens Mountain volcanic sequence. Both are genuinely remote — high, dry, silent country where the nearest petrol station can be a long drive away. It is a fittingly stark birthplace for a gem that seems to carry its own light.

The colours, at a glance

Because copper drives the colour, Oregon sunstone behaves less like one gem and more like a family of them. Broadly, dealers sort it like this:

Fine reds and greens from these deposits can command serious prices for an American gem, while pretty champagne stones remain genuinely affordable — one of the reasons rockhounds love the place.

A stone people knew long before Oregon existed

Indigenous peoples of the region collected and valued these stones long before there was a state called Oregon, and the sunstone fields lie within lands Native communities have known for countless generations. A traditional account often retold about the stone — and we share it respectfully as tradition, not history — tells of a great warrior wounded by an arrow, whose blood fell upon the stones and carried his spirit into them, giving the red ones their colour and their power. Whatever one makes of legends, the reverence is real, and far older than any mining claim.

The commercial chapter begins around the turn of the twentieth century. As the story is commonly told, Tiffany & Co. acquired claims near Plush in the early 1900s, opened what is often described as the first commercial sunstone mine in the United States, and marketed the clear stones as "plush diamonds". Accounts differ on how the venture ended — some say the claims were sold within a decade or so, others that the firm held on far longer — but by every telling it never quite took off, and the episode's real legacy was the gem's first taste of fame. Serious interest revived in the 1980s after fresh deposits came to light, and the 1987 state-gemstone designation sealed its place in Oregon identity. It is a familiar arc to anyone who enjoys gem history: the most famous stones in history tend to be made by their stories as much as their chemistry.

Yes, you can dig your own — for free

Here is the part that surprises people most. The Bureau of Land Management maintains the Sunstone Public Collection Area in Rabbit Basin, roughly 24 miles north of Plush, where anyone may hunt sunstones free of charge and keep what they find for personal use. There is no fee and no permit for casual collecting; taking stones to sell is not allowed. Facilities amount to a pit toilet, a few picnic tables and a shade shelter, and camping within the area is permitted. Go prepared, though: there are no services, no water and no mobile signal for a long way in any direction, the gravel roads reward good clearance and a proper spare tyre, and the public ground is bordered — and in places dotted — by private mining claims that must be left alone.

If you would rather stack the odds, commercial fee-digging mines work the same high-desert country. The Dust Devil and Spectrum sunstone mines, both reached via Plush, let visitors dig, screen ore or pick stones straight off a conveyor for a fee — mostly in the warmer months, when the roads behave. It is one of only a handful of places in America where an ordinary family can drive out and come home with genuine gemstones they found themselves — the sunstone equivalent of Arkansas's dig-your-own diamond crater.

An honest word about wearing it

We would be doing you no favours if we skipped this. Oregon sunstone sits at roughly 6 to 6.5 on the Mohs hardness scale — softer than quartz, far softer than sapphire or diamond — and, like all feldspars, it has cleavage planes along which a hard knock can cause splitting. In practice that makes it a lovely stone for pendants, earrings and brooches, and a reasonable one for occasional-wear rings in a protective bezel setting. As the centre stone of an everyday engagement ring, it will pick up scratches and dulled facets over the years. For a ring that must survive daily life for decades, diamond's hardness of 10 is the reason it remains the default — a difference we unpack in our guide to lab-grown and natural diamonds.

At Signora we work with lab-grown diamonds rather than sunstone, but we understand exactly why this gem inspires such devotion: it is honest, traceable and born of a real place. Those happen to be the values we build every piece around — each ring made to order in our Surat workshop, set with an IGI-certified lab-grown diamond whose report number is laser-inscribed on the girdle, and delivered to the US, UK or Canada with duties prepaid in about two weeks. If a stone with a story is what you are after, our engagement rings are a quiet place to start.