Mining and energy accounted for 1% of the GDP, which grew by 2% in 2001. Djibouti has been known to produce occasional small quantities of clays, granite, limestone, marble, salt, sand and gravel, and crushed and dimension stone for domestic construction projects. There was no cement production in the country; most imports came from Persian Gulf countries. Other mineral occurrences of potential economic interest included diatomite, geothermal fluids and mineral salts, gold, gypsum, perlite, petroleum, and pumice. Salt was extracted from evaporated pans by artisanal miners in the marshes of Tadjoura; production of salt, which was exported to Ethiopia, increased to 135,933 tons in 2000 from 82,876 in 1998. Lime was produced from an old limestone quarry just west of Djibouti city. The government hoped to establish, by the end of 2002, a fiscal, institutional, and legal framework to support the development of domestic natural resources. The government also planned to promote the use of local materials in construction and public works. The outlook for the mineral industry was for little growth in the short run; constraints included small domestic markets, minimal known natural resources, and slow GDP growth.