Custom pendant. 6-ct Oregon sunstone, octagonal cut, diamonds, and platinum. © J. Grahl Design. Used with permission.
While feldspar sunstones from sources around the world have been used for carvings and cabochons, Oregon sunstone material has proven to be facetable as well. Substantial amounts of high-value Oregon sunstone rough are now being extracted from its namesake state. Oregon sunstone is a variety of labradorite that frequently displays a stunning aventurescence, or “glowing” or “glittery” schiller effect, caused by copper inclusions. Although intense red and transparent stones with schiller are very desirable, many color varieties are found in Oregon, with and without the glowing effect.
Oregon Sunstone Value
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 schiller, commonly range up to $50 per carat, depending on the effect. Opaque cab-type stones are modestly priced. Some greens, strong pinks, and reds, as well as bicolored and tricolored 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.
Carved Oregon sunstone pieces are valued as much for their artistic merit as for the material itself.
“Sunstone Carving,” a freeform Oregon sunstone carving by Martha Borzoni of Different Seasons Jewelry, by Jessa and Mark Anderson is licensed under CC By 2.0
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
Oregon Sunstone Information
| Data | Value |
| Name | Oregon Sunstone |
| Is a Variety of | Feldspar |
| Crystallography | Triclinic |
| Refractive Index | 1.560 - 1.572 |
| Colors | Shades of pink, tan, orange, yellow, green, blue-green, red, and clear as well as bi-colors. |
| Luster | Vitreous |
| Polish Luster | Vitreous |
| Hardness | 6 - 6.5 |
| Specific Gravity | 2.71 - 2.73 |
| Birefringence | 0.008 |
| Cleavage | Perfect two directions. |
| Heat Sensitivity | No |
| Wearability | Poor |
| Special Care Instructions | Avoid rough handling |
| Transparency | Transparent to opaque |
| Phenomena | 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). |
| Pleochroism | Usually absent in feldspar but notable in Oregon sunstone. (See “Identifying Characteristics” below). |
| Optics | a = 1.559-1.563; γ = 1.569-1.573. Biaxial +. |
| Etymology | After the state and the “sun-like” golden red schiller effect found in some of these stones. |
| Occurrence | Basalt flows |
| Inclusions | Copper inclusions. (See “Identifying Characteristics” below). |
Labradorite (Feldspar), “Oregon Sunstone,” showing color range (~ 1 to 5)
Comments
Gem collectors and jewelry lovers from all over the world are fast becoming aware of this uniquely American gemstone. While many varieties of feldspar can display aventurescence and are referred to as “sunstone,” this effect is typically caused by inclusions of hematite or goethite. 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 these gems highly desirable as faceted jewelry stones.
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.
Although they share a name (and pleochroism, the showing 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.”
“Oregon Sunstone,” twisted top emerald cut, 2.57 cts. © Dan Stair Custom Gemstones. Used with permission.
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 four different varieties: threads, spots, sheets, and clouds.
Pleochroism
| Stone Color | Pleochroism |
| Yellow | colorless/light yellow |
| Red-orange and blue-green | blueish green/light red |
| (multicolored) | violet /reddish orange |
| Blueish green | blueish green/light orange/ colorless |
| Red orange | orange/light reddish purple |
| Orange | orange/reddish orange |
| Yellowish green | blueish green/light orange |
| Blue-green and violet | red-violet/reddish orange/ blueish green |
Synthetics
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 pieces.
Enhancements
Although plagioclase feldspars such as andesine can be enhanced with the addition of copper through heating and pressure treatments, Oregon sunstone is not known to be enhanced or treated. It acquires its copper naturally.
Sources
Oregon sunstone has been found in Harney County and Lake County, Oregon. Most of this material is mined by companies on private claims. However, there is a public Sunstone Collection Area in Lake County.
“Feldspar var. Sunstone (rough and cut set),” Plush, Lake County, Oregon, USA. 2.7 x 1.7 x 0.9 cm (natural crystal), 3.57 cts (brilliant oval cut gem). © Rob Lavinsky, www.iRocks.com. Used with permission.
Care
Because of their hardness rating 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 scratch gems with a hardness of 6.
The best cleaning method for Oregon sunstones is warm water, detergent, and a soft brush. Avoid mechanical cleaning methods such as ultrasonic systems and steam. Consult our Gemstone Jewelry Cleaning Guide for more information.
“Oregon Sunstone,” Portuguese brilliant cut, a peachy straw-yellow color, 4.20 cts. © Dan Stair Custom Gemstones. Used with permission.
 | Oregon Sunstone Buying Guide |
