Bulgaria was an important regional producer of nonferrous metal ores and concentrates, and was mostly self-sufficient in mineral requirements. Mining and metalworking in the region was well documented by Roman times, when Bulgaria and Romania, known respectively as Thrace and Dacia, were important sources of base and precious metals. Small quantities of bismuth, chromite, copper, gold, iron, lead, magnesite, manganese, molybdenum, palladium, platinum, silver, tellurium, tin, uranium, and zinc were mined, as well as the industrial minerals anhydrite, asbestos fiber, barite, bentonite, common clays, refractory clays, dolomite, feldspar, fluorspar, gypsum, kaolin, industrial lime, limestone, nitrogen (in ammonia), perlite, pyrites, salt (all types), sand and gravel, silica (quartz sand), calcined sodium carbonate, dimension stone, sulfur (content of pyrite), sulfuric acid, and crushed stone. Most of the copper deposits were within a roughly 50 km-wide (30 mi) swath from Burgas in the east, to the former Yugoslavia in the west, and almost all was produced by two enterprises, Asarel-Medet, at Panagurishte, and Elatzite-Med, at Srednogorie; copper was also mined at Burgas and Malko Turnovo. Lead and zinc were mined chiefly in the Rhodope Mountains, at Madan and Rudozem. Production outputs for 2000 were: gold, 2,347 kg in 2000, down from 3,390 in 1996; gross copper, 22.8 million tons; barite ore (run of mine), 8.75 million tons, up from 285,000 in 1997, 452,197 in 1998, and 1.12 million in 1999; limestone and dolomite, 11 million tons; industrial lime, 1.39 million tons; and silica, 690,000 tons. Manganese ore production was zero in 1999 and 2000; it was 55,600 tons in 1998.
Navan Resources, of Ireland, obtained a new exploration license for gold in "highly prospective" southeastern Bulgaria. The Krumovgrad region, already known for the presence of epithermal gold mineralization, showed 110 million tons of ore grading 2.2 grams per ton gold and 8.8 grams per ton silver. Navan was also exploring a promising copper mineralization at Pozharevo, in western Srednegoria, and had a 92% interest in the Chelopech gold and copper mine. The UK's Hereward Ventures won a tender for the Dikanyite exploration license, south of Sofia, a gold-producing area in antiquity that was associated with shear zones. The Asarel-Medet copper mining and beneficiation complex was privatized in 1999 through a management-employee buyout. In 2000, 80% of KCM SA, the country's producer of lead and zinc, was sold to its management.
In 1998, the National Program for Sustainable Development of Mining in Bulgaria was drafted and approved, and the Underground Resources Act was enacted. The latter, which aimed to promote private enterprise and foreign investment, stipulated that underground mineral wealth was the property of the state, and provided for claims by domestic and foreign companies for the development and operation of mineral deposits for up to 35 years with potential 15-year extensions. Improved economic performance at the end of the 1990s, the significant shift away from economic uncertainties during the transition from central economic planning, improving political stability in the Balkans, and greater investor confidence in the legal underpinnings of the growing privatization process combined to contribute to the $1 billion net foreign investment in 2000, one-third more than in 1999.