Mined in the Pacific Northwest, this princess-cut American Mined™ Oregon Schiller Sunstone™ brings an exciting orange/peach/pink color and a rich presentation of the sunstone's signature Schiller effect (shimmer) to all types of jewelry designs. match it with gems of similar or complementary colors, or use a pair to make earrings. Sunstone is an orthoclase feldspar, which contains potassium and displays a brilliant spangled appearance, making it a popular choice as a gemstone. This spangled look, called the 'schiller' effect is caused by small, flat reflective inclusions that align themselves along the mineral structure. Rio is proud to offer the American Mined™ Collection, a growing selection of gemstones sourced from mines located here in America. These gemstones consistently present the excellent color, clarity and quality we look for in every gem we offer you. Each of these gemstones allows us to provide a clear, documentable path from the mine to your bench; you and your customers can be confident that every one is mined, cut and processed under conditions that meet all standards for worker safety, environmental protection and responsible production. The princess cut creates a square gemstone and requires a greater depth in order to achieve the desired brilliance.