As early as 1,000 BC, the inhabitants of the Arabian Peninsula extracted gold, silver and copper from the mine called Mahd Al-Dhahab (Cradle of Gold), located about 180 miles northeast of Jeddah. Once the greatest gold mine in all of the Middle East and Africa, it is now being worked again as the most advanced project in Saudi Arabia's effort to diversify its sources of income by establishing a mining industry. Several other gold mines have been explored and substantial reserves identified. Modern mineral exploration, in fact, has unearthed not only gold, silver, and copper, but also tin, tungsten, nickel, chrome, zinc, lead, phosphates, iron ore, uranium, bauxite, potassium ore and even table salt. The Kingdom is probing the mineral-rich sediments on the Red Sea floor for commercial exploitation, and operating a pilot plant to process these at Yanbu. In 1996, the government committed to an investment of 1.74 billion U.S. dollars to expand the mining industry, especially in phosphates.