Sonoran Blue Gold Canyon Turquoise is an interesting turquoise from Senora, Mexico, near Nogales, Arizona, and its neighbor: Nogales, Mexico, which is the northernmost point in all of Mexico. The series of mines bearing this name are on several sites contingent to the American border. Very little hard natural material has been mined here. Most has needed stabilizing to be useful. The high-grade natural material is a medium blue, with darker blue matrix, forming a "birds’ eye" pattern. This is usually accompanied by iron pyrite, giving it a similar look to a high-grade Morenci. The high-grade turquoise from this mine is rare and is considered both esoteric and valuable. These "mini" stud earrings are the perfect size. Measuring only 3/8" x 1/4". Set in solid sterling silver with genuine high grade Sonoran Gold Turquoise. Sterling Silver posts and backings.