The mining sector of Fiji contributed 3% to the GDP, virtually all of it from gold, the only metallic mineral recovered in Fiji in 2001. Gold was the third-leading export commodity in 2002, generating 6% of Fiji's foreign exchange. The sole gold producer, Emperor Mines Ltd., was the largest private employer, with more than 1,600 employees. Gold has been mined and exported continuously since 1933. The country was also richly endowed in deposits of copper, lead, and zinc. Gold and silver ranked fourth and fifth among Fiji's top industries in 2002, although no figures were available for the year. Production of gold rose steadily in the mid-1990s, reaching 4,671 kg in 1997; it has since remained static, with the 2001 total at 3,858. Hydraulic cement production was 95,000 tons in 2001. In 2001, Fiji also produced crushed and dimension stone, sand and gravel, and sand for cement manufacture. No silver was mined in 2001; 1,475 kg was mined in 2000 and 2,594 in 1997. In addition to resources at existing sites, 930 million tons of copper (in Viti Levu) and gold reserves have been reported, and prospecting continued for oil and phosphates, and at base-metal sulfide deposits, disseminated porphyry copper deposits, epithermal precious-metal deposits, residual bauxite deposits, and manganese and heavy-mineral sand deposits that have previously been identified and evaluated. None has been shown to have sufficient tonnage to be economically viable. Ownership of minerals was vested in the state, which granted mining and prospecting rights.