Mercury sulfide Mercury sulfide Mercury sulfide, mercuric sulfide, mercury sulphide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water. HgS is dimorphic with two crystal forms: Crystals of red, α-HgS, are optically active. This is caused by the Hg-S helices in the structure. β-HgS is precipitated as a black powder when HS is bubbled through solutions of Hg(II) salts. β-HgS is unreactive to all but concentrated acids. Mercury metal is produced from the cinnabar ore by roasting in air and condensing the
Ore Mountains sharply defined because the Ore Mountains, a typical example of a fault-block, descend very gradually. The topographical transition from the Western and Central Ore Mountains to the loess hill country to the north between Zwickau and Chemnitz is referred to as the Ore Mountain Basin; that from the Eastern Ore Mountains as the Ore Mountain Foreland. Between Freital and Pirna, the area is called the Dresden Ore Mountain Foreland ("Dresdner Erzgebirgsvorland") or Bannewitz-Possendorf-Burkhardswald Plateau ("Bannewitz-Possendorf-Burkhardswalder Plateau"). Geologically the Ore Mountains reach the city limits of Dresden at the Windberg hill near Freital and the Karsdorf Fault. The V-shaped valleys of