Metal and metal products, particularly aluminum and steel, comprised Slovakia's leading industry in 2002—based almost entirely on imported raw materials. Gas, coke, oil, nuclear fuel, and chemicals were other top industries. Industrial mineral production in 2000 included: dolomite, 1.5 million tons, down from 2 million tons in 1997; lime (hydrated and quicklime), 700,000 tons; magnesite concentrate, 1 million tons, up from 824,800 in 1996; crude gypsum and anhydrite, 120,000 tons; salt, 121,700 tons; barite concentrate, 13,700 tons, down from 62,102 in 1997; bentonite, 77,000 tons; kaolin, 21,000 tons; perlite, 17,020 tons, down from 24,240 in 1998; and zeolites, 10,000 tons. The Kosice magnesite mines were put on care-and-maintenance. Also produced in 2000 were arsenic, diatomite, feldspar, illite, iron ore, refractory clays, nitrogen, sand and gravel, sodium compounds, limestone and other calcareous stones, crushed stone, sulfur, sulfuric acid, and talc. No zinc, lead, gold, silver, or copper was mined in 2000. Other mineral resources included antimony ore, mercury, brick soils, ceramic materials, and stonesalt. All mining companies were government owned.