Emerald mining is almost exclusively done from host rocks, where the emerald has grown into small veins or on walls of cavities.
Colombia is the international center of emerald mining. The Muzo Mine, northwest of Bogotá, produces fine-quality stones of a deep green color. The Chivor Mine, northeast of Bogotá, is another important deposit, and other locations promise additional successful mining results.
Brazil has various deposits in Bahia, Goias and Minas Gerais. The stones are lighter than the Colombian ones; mostly yellow-green and are often free of inclusions. Brazil also supplies rare emerald cat’s eyes and extremely rare emeralds with a six-ray star.
South African deposits are concentrated in the Northern Transvaal. But only five percent of the stones found in the Cobra and Somerset Mines are of good quality. Most stones are light or muddy and are only suitable for cabochon cuts.
Zimbabwe has several deposits of emerald; the most important is the Sandawana Mine in the south. The crystals are small, but of very good quality. Russia has deposits in the Ural, north of Sverdlovsk. Good quality emeralds are rare; most stones are light or muddy and only suitable for cabochons. Further deposits are in Afghanistan, Australia (New South Wales and Western Australia), Ghana, India, Madagascar, Malawi, Mozambique, Namibia, Nigeria, Pakistan, Tanzania, Zambia and the United States (North Carolina).