Sunstone is a unique gem which when viewed from certain directions exhibits a brilliant spangled appearance. The optical effect appears to be due to reflections from inclusions of red copper inclusions. These inclusions give the stone an appearance something like that of aventurine, hence sunstone is known also as "aventurine-feldspar."
The optical effect called shiller and the color in Oregon Sunstone is due to copper. The middle part of this crystal sparkles, and usually the color is darkest in the middle and becomes lighter toward the outer edges.
Sunstone is popular with innovative jewelry designers and is especially popular in the geographic areas where it is commercially mined. It is not a gemstone that is seen in every jewelry store, and many jewelry buyers have never witnessed its aventurescence. However, once a person is given a demonstration of sunstone’s aventurescence, they often want to try it and are fascinated.