New Almaden hydrothermal deposition of cinnabar from deep within the earth is found in a gangue of silica-carbonate rock formed locally by hydrothermal alteration of serpentine. The Guadalupe mine produced about 10% as much mercury as the New Almaden. There are several smaller mines in the mining district, but their ore production was not significant. The only significant quicksilver ore is cinnabar; other sulfides are present in small quantities. Mining, other than a single placer deposit of cinnabar, was underground. There is a high probability of undiscovered high-grade ore which could be found and exploited using modern techniques. Mining operations resulted in
Ore Mountains Mountains in the vicinity of newly discovered ore deposits. Typical examples are the towns of Marienberg, Oberwiesenthal, Gottesgab ("Boží Dar"), Sebastiansberg ("Hora Sv. Šebestiána") and Platten ("Horní Blatná"). Economically, however, only silver and tin ores were used. From that time, the wealth of Saxony was built on the silver mines of the Ore Mountains. As a metal used for coinage, silver was minted on site in the mountain towns into money. The "Joachimsthaler" coins, minted in the valley of "Joachimsthal", became famous and gave their name to the medieval coin known as the "Thaler" from which the word "dollar" is