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
Iron ore over a slurry containing magnetite or other agent such as ferrosilicon which increases its density. When the density of the slurry is properly calibrated, the hematite will sink and the silicate mineral fragments will float and can be removed. Iron is the world's most commonly used metal - steel, of which iron ore is the key ingredient, representing almost 95% of all metal used per year. It is used primarily in structural engineering applications and in maritime purposes, automobiles, and general industrial applications (machinery). Iron-rich rocks are common worldwide, but ore-grade commercial mining operations are dominated by the countries listed