Oregon produces some of the best gem-quality feldspars in the world. Several small mining operations have become world-famous for producing “Oregon Sunstone,” a transparent feldspar that is loaded with tiny copper platelets aligned in a common orientation. When a sunstone is tilted in the light, at just the right angle, these platelets simultaneously reflect a flash of light.

Oregon produces several other gem materials including the famous “thunderegg,” a type of geode that is ugly on the outside but often filled with beautiful chalcedony, opal, or crystals inside. Some people argue that thundereggs are more popular than sunstone! Oregon also produces a number of different fire opals and common opals with beautiful colors. There are several pay-to-dig sites in Oregon where you can find sunstone, opal, thundereggs and more.