Oregon sunstone is a feldspar crystal formed in molten lava and then discharged onto the surface of the earth by a volcano. As the lava weathers away or is broken up the crystals are released.

While feldspars are found all over the world, they are rarely gem grade. Central Oregon is the only place in the world where gem grade Sunstones are found containing copper, and are large enough to cut stones for jewelry. 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. Some rare stones will even change colors in different light as alexandrite does, and some are different colors when viewed from different directions (dichroic and trichroic).