While feldspar sunstones from sources around the world have been used for carvings and cabochons, Oregon sunstone material has proven to be facetable, too. These stones frequently display a stunning glowing or glittery optical effect.
Oregon Sunstone
Value
Start an IGS Membership today for full access to our price guide (updated monthly).
Pale yellow to colorless, non-phenomenal Oregon sunstones, whether native-cut or calibrated stones, may go for a few dollars per carat to $20 per carat for a custom cut. Pinks and tans, with and without a schiller effect, commonly range up to $50 per carat, depending on the effect.
Opaque, cabbed stones are modestly priced. Some greens, strong pinks, and reds, as well as bi-colored and tri-colored stones, with and without schiller, range from $50 to $300 per carat.
Large stones (over three carats) with an intense red color may retail for as much as $1,700 per carat. The best greens are very rare and may cost more than the best reds.
Aventurescence or schiller effect. (See “Identifying Characteristics” below).
Formula
Oregon sunstone is a variety of labradorite, a mineral in the plagioclase feldspar solid-solution series, with a composition of 32% albite (NaAlSi3O8) and 68% anorthite (CaAl2Si2O8).
Gem collectors and jewelry lovers from all over the world are fast becoming aware of this uniquely American gemstone. While many varieties of labradorite feldspar can display aventurescence or schiller and are commonly called “sunstones,” those effects are typically caused by inclusions of hematite or goethite. In contrast, the labradorite sunstones found in Oregon have inclusions of copper. This unique happenstance means these gemstones may both display a schiller effect and transparency. This makes them highly desirable as faceted jewelry stones.
Intense red and transparent gems with schiller are in great demand. However, many color varieties occur in Oregon, with and without the glowing effect.
Although a relative newcomer to many in the gem buying public, Oregon sunstone has traditionally been valued and traded by the Native Americans of the Pacific Northwest. In 1987, Oregon officially declared it its state gemstone. In the esoteric realm of birthstone mythology, sunstones are considered the phenomenal birthstone for those born on Sunday.
Is Oregon Sunstone the Same Thing as Viking Sunstone?
Although they share a name (and pleochroism, the display of two or more colors when viewed from different angles), Oregon sunstones are not the so-called “sunstones” Vikings reputedly used to navigate on overcast days or when the sun was low in the Arctic sky. Pleochroic iolite was most likely the “Viking Compass.”
Identifying Characteristics
Inclusions
The only feldspar sunstone with copper inclusions is Oregon sunstone. However, not all specimens display the schiller effect. The copper inclusions in Oregon sunstone come in varieties like threads, spots, sheets, and clouds.
Oregon sunstones have not been synthesized. However, goldstone, a synthetic material made of glass with copper inclusions, may be used as a simulant. A gemologist can easily distinguish a natural Oregon sunstone from one of these glass pieces.
Substantial amounts of high-value Oregon sunstone rough are now being extracted from its namesake state.
Harney County and Lake County, Oregon produce Oregon sunstone. Companies on private claims mine most of this material. However, there’s a public Sunstone Collection Area in Lake County.
Because of their hardness of 6 to 6.5, Oregon sunstones are best suited for jewelry such as pendants, earrings, brooches, or other pieces that won’t endure heavy wear. Common dust has a hardness of 7 to 7.5 and will scratch this material. Steel can also scratch gems with a hardness of 6. For ring use, place Oregon sunstones in protective settings.