The mining and quarrying industry was projected to produce 1.5 percent of GDP in 1991. Limestone--used in cement production--and clay were the major minerals being extracted in the mid-1980s. Mineral production also has included marble, dolomite, graphite, and slate. In addition, deposits of copper, gypsum, lead, tin, tungsten, zinc, coal, beryl, mica, pyrites, tufa, and talc have been found, primarily through an exploration program operated initially by the Geological Survey of India and, starting in 1982, in cooperation with the Geological Survey of Bhutan. Although not being exploited as much as other minerals, Bhutan's slate deposits have been described by experts as some of the best in the world. Bhutan's high-quality limestone deposits and energy resources were expected to take on increasing importance in the 1990s because of the contributions they could make to the ferro-silicon industry, which the government hoped to invest in through Bhutan Carbide and Chemicals.
Data as of September 1991