Mercury sulfide, cinnabar

Cadmium sulfides and selenides group Mercury group Cadmium mercury sulfide Cinnabar Hypercinnabar Mercury(ll) sulfide, cinnabar type Mercury(ll) sulfide, metacinnabar type Vermilion... 

The toxic effects of mercury and mercury compounds as well as their medicinal properties have been known for many centuries. In the first century AD, Pliny indicated the use of mercuric sulfide (cinnabar or vermilion) in medicine and in cosmetics. This compound was probably known to the Greeks in the time of Aristotle (13). 

C21-0078. The only important ore of mercury is cinnabar, HgS. In contrast, zinc is found in several ores, including sulfides, carbonates, silicates, and oxides. Explain these observations in terms of hard and soft acids and bases. 

Vermilion and cinnabar are two bright red, toxic minerals that share an identical composition (they are both composed of mercury sulfide) but have different crystal structures. Two kinds of vermilion are known one of natural origin and another made artificially. Finely ground natural vermilion may vary in hue from red to liver-brown and even to black. Artificial vermilion was made from mercury and sulfur the method of preparation seems to have been developed by the Chinese and was introduced into Europe only during the eighth century c.e. (Gettens et al. 1972). 

Mercury occurs in soils predominantly in the +2 oxidation state. Elemental Hg in the atmosphere is oxidized to Hg + and deposited in rainfall. It is a strong chalcophile and under anaerobic conditions forms the extremely insoluble sulfide cinnabar (HgS, pK = 52.7). Nonetheless it is not entirely immobilized under anaerobic conditions because it is reduced to volatile Hg° or methylated to volatile methyl mercury compounds by microbial action, and so returned to the atmosphere. The methylation is mediated by various bacteria, especially methanogens, through the reactions ... 

Mercuric sulfide (HgS) is a fine, very brilhant scarlet powder that is deadly if ingested. Also known as the mercury ore cinnabar and metacinnabar, it is used as a pigment in the manufacture of paints. 

Mercury, for example, could be dissolved in acid or converted to a calx, and from either the mercury could be obtained again in metallic form. It could be combined with mineral sulphur to make cinnabar (mercuric sulfide), a more convenient form for transportation than the heavy liquid metal. To get the metallic mercury back, the artificial cinnabar was heated with lime thirteen and half ounces of mercury can be obtained from a pound of artificial cinnabar. Lemery speaks of the cause of this disguise of Mercury in Cinnabar... 

Between the years 1400 and 1890 the reds that artists used were extracted from plants, such as madder, or from crushed insects, such as the scale insect Dactylopius coccus, or were of mineral origin, such as cinnabar (mercury sulfide, HgS) which could be ground to a powder to produce the pigment vermilion which was much used in antiquity, or red iron oxide (Fe203) which was used by the Neolithic cave painters, or minium (red lead, Pb304). 

Pyrite and marcasite have been faceted and used in jewelry. Galena, cinnabar, and other sulfides have been ground up and used as pigment and in cosmetics and medicine. Cinnabar is the red sulfide of mercury. Chinese cinnabar tableware and jewelry is actually layered lacquer that was... 

Before ad 1500, many alchemists thought that matter was composed of two "elements" mercury and sulfur. To impress their patrons, they performed an experiment with mercury sulfide, also called cinnabar, HgS. They heated the red cinnabar, which drove off the sulfur and left the shiny liquid mercury. On further heating, the mercury reacted to form a red compound again. Alchemists wrongly thought that the mercury had been converted back to cinnabar. What Hg(ll) compound do you think was really formed when the mercury was heated in the air What is the mass percent of mercury in this new compound What is the mass percent of mercury in cinnabar ... 

Mercury. In recovering mercury from cinnabar ores, the ore is crushed to minus 1.5 cm and fed to rotary kilns, where it is calcined to over 800 K. Since the mercury exists as mercuric sulfide (HgS), the sulfur is oxidized to SO2 and the mercury vaporized. The gases are passed through cooling chambers, where the mercury condenses and is collected. Mercury vaporizes at 625 K. 

The most common source of mercury is cinnabar (HgS), whereas Zn and Cd in the same group occur as sulfide, carbonate, silicate, and oxide. Why ... 

Sulfur also occurs in a number of important minerals. Some examples are barite, or barium sulfate (BaS04) celestite, or strontium sulfate (SrS04) cinnabar, or mercury sulfide (HgS) galena, or lead sulfide (PbS) pyrites, or iron sulfide (FeS2) sphalerite, or zinc sulfide (ZnS) and stibnite, or antimony sulfide (Sb2S3). 

Several forms of mercury occur naturally in the environment. The most common natural forms of mercury found in the environment are metallic mercury, mercuric sulfide (cinnabar ore), mercuric chloride, and methylmercury. Some microorganisms (bacteria and fungi) and natural processes can change the mercury in the environment from one form to another. The most common organic mercury compound that microorganisms and natural processes generate from other forms is methylmercury. Methylmercury is of particular concern because it can build up in... 

The bulk of the information regarding toxicity resulting from oral exposure to inorganic mercury comes from studies of mercuric chloride. However, a few studies are also available on the effects of oral exposure to mercuric acetate, mercurous chloride (calomel), and mercuric sulfide (cinnabar). Discussion of these compounds has not been separated in this section, but the specific inorganic compound responsible for any effect is noted both in the text and in Table 2-2 and Figure 2-2. 

Synonym(s) Colloidal mercury liquid silver mercury, metallic (DOT) quicksilver metallic mercuryb hydrargyrum0 Bichloride of mercury mercury bichloride01 mercury chlorided mercury dichloride mercury perchloride mercury (II) chloride perchloride of mercury corrosive sublimated corrosive mercury chloride dichloromercury Etiops mineral0 mercury sulfide, blackd vermilion Chinese red C.l. Pigment Red 106 C.1.77766° quicksilver vermilion Chinese vermilion red mercury sulfide artificial cinnabar red mercury sulfuretd... 

Mercury is a naturally occurring element that is usually found as mercuric sulfide (cinnabar), an insoluble, stable compound. It occurs in the earth s crust at levels averaging 0.5 ppm, but the actual concentration varies considerably depending on location (Merck 1989 Sidle 1993). Mercury is mined using both open pit (10% of production) and underground mining techniques (90%) (Drake 1981). 

Mercury is a unique element. An extremely heavy metal, it is the only metallic element that exists in liquid form at room temperature. This silvery white metal is a good conductor of electricity, but it is a poor conductor of heat, which is unusual for metals. Scientists have shown that mercury has been known to humanity for thousands of years. People in ancient China knew of the metal, and samples of it have been found in Egyptian tombs dating back to 1500 b.c. While its name comes from the planet Mercury, its chemical symbol, Hg, comes from the Latin word hydragyrum, which means liquid silver. Mercury s primary ore is cinnabar, which is also known as vermillion. This ore, found chiefly in Spain and Italy, contains an abundance of mercury sulfide compounds. Mercury is extracted from cinnabar by heating the ore and then condensing the resulting vapor. 

Figure 4.6 This is a sample of the ore cinnabar (vermillion). Cinnabar contains high concentrations of mercury sulfide and is the chief ore from which mercury is extracted.

The alkaline earth group as a whole stands in marked contrast to transition metals and post-transition metals. For example, most of the metals in the periodic table form insoluble precipitates with the sulfide ion (S2), with the result that sulfide ores of transition and post-transition metals are very common in Earths crust. Common examples of metal sulfides include galena (lead sulfide), cinnabar (mercury sulfide), gree-nockite (cadmium sulfide), acanthite (silver sulfide), cobaltite (cobalt arsenic sulfide), sphalerite (ZnS), stibnite (antimony sulfide), several copper sulfides, orpiment and realgar (both forms of arsenic sulfide), and pyrite (iron sulfide). None of the alkaline earths, however, are found as sulfides. 

Human activities have resulted in the release of a wide variety of both inorganic and organic forms of mercury. The electrical industry, chloro-alkali industry, and the burning of fossil fuels (coal, petroleum, etc.) release elemental mercury into the atmosphere. Metallic mercury has also been released directly to fresh water by chloro-alkali plants, and both phenylmer-cuiy and methylmercury compounds have been released into fresh and sea water -phenylmercury by the wood paper-pulp industry, particularly in Sweden, and methyl-mercury by chemical manufacturers in Japan. Important mercury compounds which also may be released into the environment include mercury(II) oxide, mercury(II) sulfide (cinnabar), mercury chlorides, mer-cury(II) bromide, mercury(II) iodine, mer-cury(II) cyanide, mercury(II) thiocyanate, mercury(II) acetate, mercury nitrates, mercury sulfates, mercury(II) amidochloride monoalkyl- and monoarylmercury(II) halides, borates and nitrates dialkylmercury compounds like dimethylmercury, alkoxyal-kylmercury compounds or diphenylmercury (Simon and Wiihl-Couturier 2002) (for quantities involved, see Section 17.4). 

PHYSICAL PROPERTIES most inorganic mercury compounds are white powders or crystals mercuric sulfide (cinnabar) is red and turns black when exposed to light insoluble in hydrochloric or similar acids soluble in nitric acid and hot concentrated sulfuric acid water soluble salts include mercuric chlorate, cyanide, chloride and aeetate oxides, sulfates and most other common salts, including mercurous chloride, are sparingly soluble or deeomposed in water appearances vary from eolorless crystals to yellow, red (oxide, sulfide, iodide), and brown or black (sulfide) MP (-39°C, -38°F) BP (357 C, 674 F) DN (13.534 gW at 25°C) SG (13.5) VD (not applicable) VP (0.0012 mitiHg at 20°C). 

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