Oregon Symbols, Gemstone: Sunstone

Adopted on August 4, 1987.

The 1987 Legislature designated the Oregon sunstone as the official state gemstone. Uncommon in its composition, clarity, and colors, it is a large, brightly colored transparent gem in the feldspar family occur in Lake and Harney Counties where they are dug from the soil and the underlying lava flows.

Sunstone is an ancient gem, in fact sunstones have been discovered in Viking Burial mounds. Sunstone also occurs in Tvedestrand, Norway; near Lake Baikal, Russia; Middletown, PA., and Statesville, NC. Only the Oregon Sunstone has the copper inclusions giving it the unique colors. The Oregon sunstone attracts collectors and miners and has been identified as a boon to tourism and economic development in southeastern Oregon counties. For many years, collectors have prized sunstones from eastern Lake County, near Plush, Oregon, where the U.S. Bureau of Land Management has established a free, public collecting area. Until recently, this was the only known occurrence.

The premier U.S. gem-quality feldspar is the red labradorite, known as sunstone, mined in Oregon. Large quantities of gem-quality labradorite, most of it water-clear, straw yellow, or yellow sunstone, has been produced from deposits in southeastern Oregon for many years. In sunstone, the labradorite contains millions of copper platelets that reflects the light with varying intensities resulting in a golden-red play of color known as schiller. Although the common color of Oregon sunstone is straw-yellow, it also can be pink, peach, red, salmon red-orange, red-green, and blue-green. It also can be bicolored and tricolored in combinations of yellow, red, and green, and a small percentage is di- and tri-chroic.

Oregon sunstones are uncommon in their composition, clarity, and range of colors and occur in sufficient abundance to permit sustained production of faceted gems. These color variations and the shimmer (often called "schiller") are caused by tiny crystals of copper metal contained in varying amounts and sizes within the stones. The darker stones contain larger amounts of copper. The reflective inclusions or red, orange, or green platy crystals give Sunstone its metallic glitter.

In 1988, the availability and quality of sunstone, other than the standard yellow Oregon variety, drastically increased with the discovery of the deposit that was to become the Ponderosa Mine. The vivid-red faceted stones and velvety-red cabochons from this mine set a new world standard for beauty, not just for red sunstone, but for any sun-stone. The opening of the mine also increased the supply of peach, salmon red-orange, red-green, green, blue-green, and bicolored and tricolored in combinations of yellow, red, and green. For the first time ever, there was a continuous U.S. supply of the more desirable colors in most of the calibrated sizes up to several carats needed by the jewelry industry. The largest faceted high-quality red sunstone is over 10 carats. The supply from this and other developed deposits will continue to be adequate for many years into the future.

Two more occurrences in northern and southeastern Harney County have been discovered recently, allowing the mining of more marketable gems, and the geology of the area is favorable for the discovery of more deposits. Except for the BLM public collecting areas, all these producing areas are held by mining claims and are not available for collecting without permission of the claim owners.

CHEMISTRY A calcium rich species of plagioclase feldspar,
sometimes with copper or hematite inclusions and traces of iron; 32% Albite, 68% Anorthite
CRYSTALLOGRAPHY Monoclinic
REFRACTIVE INDEX 1.560 - 1.572
HARDNESS 6 - 6.5
SPECIFIC GRAVITY 2.69 - 2.72
CLEAVAGE Perfect two directions.
HEAT SENSITIVE No

WEARABILITY Poor

Lore: Among the Vikings it was thought to be an aid to navagation. The Native people in Oregon used it for trade and barter.