otswana ranks first among the world’s gem-quality diamond producers, and diamond mining makes up 70 percent of the nation’s export revenue. The Jwaneng Diamond Mine, in south-central Botswana, sits atop the convergence of three kimberlite pipes—diamond-rich geologic formations. Because the pipes meet just below the surface and cover some 520,000 square meters (128.5 acres) at ground level, the diamonds are mined from an open pit rather than a mine tunneled below the surface.
Although this photograph may appear to be a small pit mine as seen from the air, it is actually a pit mine that is about a mile wide and just over a thousand feet deep as photographed by astronauts orbiting the Earth on board the International Space Station. The New Cornelia Mine is located just south of Ajo, Arizona. Small-scale mining of copper in this area began with the Spaniards and Mexicans as early as 1750. This large-scale, systematic operation began in 1912 and expanded rapidly for the next 50 years. Since the mid 1980s, activity has been limited because of low prices for copper on the world market. Note the tailings deposits to the east (right) and the larger containment ponds for extraction processes to the northeast.
One of the largest open-pit copper mines in the world, the Cananea mine produced over 164,000 tonnes of copper in 2006. The active, 2-kilometer-diameter Colorada Pit is recognizable by the concentric steps, or benches, cut around its perimeter.
Located in the Sudirman Mountains of the Irian Jaya province of Indonesia, the Grasberg complex is one of the largest gold and copper mining operations in the world.