High Grade Natural Sierra Nevada Rectangular Turquoise Cabochon for your Jewelry Designs or Turquoise Collection Handcrafted-One of a Kind Unique Item Rectangular Cabochon Natural Sierra Nevada Turquoise Measures Approximately 23 mm in Length by 14 mm in Width 21 Carats Mined in Nevada USA Professionally Cut Lightly Backed for stability The Sierra Nevada Turquoise Mine is a owned by the Otteson Family and located in the Sierra Nevada Mountains near Tonepah, Nevada. It is close to The Royston and Candelaria Turquoise Mines.