High-grade phosphate rock was virtually Nauru's only natural resource, its only export commodity and leading industry, and the basis of the Nauruan economy—GDP varied according to the world market price of phosphate. The government-owned Nauru Phosphate Corp. was the country's sole producer of phosphate rock, and the island nation's primary producer, employer, and exporter. Production of phosphate rock in 1998 was 487,000 tons, down from 613,000 in 1994. Phosphate rock reserves were expected to be depleted by 2004. In 1998, Naura also produced common clays, sand and gravel, and stone.
Phosphate rock was extracted from the surface mine on the central plateau in the island's interior, using mechanical shovels from between the coral pinnacles. Phosphate rock was trucked to a central storage pile and transported to storage hoppers by rail. After being crushed and dried, the rock was placed on conveyor belts to pass to the arm of two cantilevers, each about 60 m long, that projected out over the reef to waiting ships. All phosphate rock was exported—to New Zealand, Australia, the Philippines, and South Korea—and the associated coral was used domestically for road aggregate.
In 1999, the government planned to launch a program to rehabilitate and develop the phosphate lands that have been mined for nearly a hundred years—as of 1990, 61 million tons of phosphate had been mined. The plan was agreed to in 1994 with Australia and New Zealand, and the United Kingdom agreed to help Australia pay its $73 million compensation package to Nauru for environmental damage; the rehabilitation would cost $210 million over 23 years. Nauru's phosphate mine was the last active mine of three historic phosphate-producing islands of the Pacific. The other two, Makatea (in French Polynesia) and Banaba (formerly known as Ocean Island, in the Gilbert Islands group in the Republic of Kiribati), were depleted, respectively, in 1966 and 1979, making Nauru the sole Pacific Island producer.