This gorgeous gemstone is a natural Red-Orange Labradorite from Oregon.
Red-orange is the 2nd most prized color for this gemstone, and this one has beautiful uniform color with only light-moderate brownish "masking" that is common to most orange to red sunstones. It is very clear, eye clean and VVS quality. Sunstones are often eye-clean but many have very tiny inclusions or bubbles, and some have very tiny flaws. They typically are VS in quality with varying degrees of masking. The gem is cut in nice, standard calibrated Cushion shape. This stone comes from the privately owned Spectrum mine near the Antelope Refuge in southeastern Oregon. The Spectrum mine is one of a small group of northwestern states gem mines that were owned by suppliers to Tiffany early in this century.
Labradorite is an ancient gem, in fact these gems have been discovered in Viking burial mounds in Labrador. It was thought that the sunstone aided in navigation. Labradorite is the State Gem of Oregon, 
where it has been collected by Native Americans for centuries. While found all over the world, feldspar crystals and "eyes" (small nodules in basalt formations) are rarely gem grade. Only Harney County and Lake County Oregon (below), have crystal deposits of gem grade and large enough to facet for jewelry. The gem is about the hardness of a good peridot--6 - 6.5 on the hardness scale and harder than Tanzanite and most gem Opal.
It is the copper and iron that that make Oregon Labradorite special. The bright copper platelets gave the name Heliolite, from the Greek helios for sun and lithos for stone. Varying amounts of copper cause the stones to range in color from water clear to yellow, as well as many shades of green, red and pink. Some stones contain from two to four of these colors, and some have pure native copper platelets that cause the stone to sparkle. This effect is called aventurescense or schiller.
