Mercury (element) long periods at elevated temperatures. It reverts to the elements upon heating near 400 °C, as was demonstrated by Joseph Priestley in an early synthesis of pure oxygen. Hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver. Being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. Preeminent is mercury(II) sulfide, HgS, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. Like ZnS, HgS crystallizes in two forms, the reddish cubic form and the black zinc blende form. The latter sometimes occurs naturally as metacinnabar. Mercury(II)
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