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 this is a contract between Boresch of Riesenburg and the Ossegg abbot, Gerwig, in which the division of revenue derived from ore was agreed. Grains of tin ("Zinnkörner" or "Graupen") were obtained at that time in the Seiffen mining area and gave the Bohemian mining town of Graupen (Czech "Krupka") its name. With the further settlement of the Ore Mountains in the 15th century, new, rich, ore deposits were eventually discovered around Schneeberg Annaberg and St. Joachimsthal. The "Second Berggeschrey" started and triggered a massive wave of colonization. In quick succession, new, planned, mining towns were built across the Ore