Vermilion - SpeedyLook encyclopedia

Composition

Vermilion (HgS alpha) is produced by the synthesis (by dry roads or wet) of sulfur and mercury. The Cinnabar, of the same composition (HgS alpha) is the native ore of mercury. One uses the vermilion term to differentiate the product of synthesis from the native ore.

Structure

Vermilion has a crystalline structure Trigonal. Mercury tends to form only two strong connections as in the Halogénure S. the group of covering is C312 or P3121. The mesh contains three molecules of HgS. The basic cell has as dimensions: a= 4,160 or 4,15 or 4,14 for c= 9,540 or 9,51 or 9,49 according to the authors. Each mercury atom is surrounded by six sulfur atoms.

Physical properties

Vermilion as cinnabar is a semiconductor.

It is photosensitive and can blacken when it is exposed in the light of the day.

Toxicology

This pigment is extremely Toxique. Any contact with the skin and the mucous membranes must be avoided.

The technical principles of prevention are the following: it is necessary to have a good ventilation system, to clean the schemes of work daily, to store out of tight containers and to eliminate the material used for cleaning from made up of mercury. The track suit of work should not comprise pockets and reverse. Concerning personal hygiene, it is recommended to regularly wash the hands and the nails, the face, the brushing of the teeth and the rinsing of the mouth. A formal prohibition to smoke, eat or of drinking on the work place.

Insofar as vermilion is Pulvérulent or is presented in the form of Poudre, of strict measurements of protection are highly recommended. The use of gloves makes it possible to be protected when toxic pigments are handled, the wearing of a mask is singularly recommended when the pigment is pulverulent, in the ideal it would have comprised a special filter for mercury, the safety goggles are also strongly advised.

Manufacture

For the preparation of vermilion, one sublimates a mixture of mercury and sulfur. Thus the synthesis of vermilion was reported by Geber to the 8th century in Persia. As from the 16th century, it would be industrially manufactured in Venice then in Holland. During the process, is formed initially a black sulfide then red. The precipitated black sulfide is known as Amorphe, it was formerly called éthiops mineral and it is produced by direct combination of sulfur and mercury when they are triturated where that they are heated. Currently, the red mercury sulfide prepares by reaction of the sulfur purified with mercury: the black resulting mercury sulfide is heated with 580°C then treated with NaOH or KOH. One can also prepare it according to a process of sulphurization hydrothermal.

History

The discovery of the synthesis of mercury sulfide was the central innovation of the medieval Period concerning art. However, this process of synthesis would have been discovered by Geber about the 8th century. While making vermilion abundant, the pallet of the painters increases and other bright colors are necessary to harmonize it. The art of this period, mainly religious is rich in vermilion, gold sheets and blue overseas, which are the three principal colors of the medieval pallet. Vermilion, of the same elementary composition as the Cinnabar, can be manufactured almost everywhere on small crucibles, and it is in particular very widespread, inter alia, like red ink in the manuscripts.

The monk Benedictine Theophilus describes the manufacture of vermilion at the end of the 11th century in the work named Schedula diversarum artium . It is necessary, of the Soufre which can be of three kinds: black, white or yellow. He is broken on a stone dries and one adds an equal share with mercury. As all is mixed and deposited in a bottle of clay glass fought so as to seal the opening of it to prevent that smoke cannot escape, one plunges it in burning coals and when the pot becomes hot, one hears crackings, it is the sulfide which links with mercury. When the noise stops, one can withdraw the pot of fire and take the pigment there. Theophilus mentions a technique or the pigment is prepared seems you it by combination of sulfur and of mercury, the pigment which results from it must consequently be rather pure although the true nature of the three type of sulfur is not known.

The alchemist Albert Large the, probably born at the beginning of the 12th century in Souabe, also called Albertus teutonicus , frater Albertus de Colonia , or Albertus magnus , is often mentioned as being the first to have carried out the synthesis of mercury sulfide lasting the medieval period. Theologist, philosopher, scientist and encyclopedist, he knew work of the Arab schools and in its treaty, he accepts and uses work Gerber by uniting his own observations there. According to him, metals are formed thanks to the mixtures of sulfide and mercury. The mercury and the sulfide are linked and combine in the ground while hardening as a Minéral from which the Métal can be extracted. It thus describes the synthesis of vermilion by Sublimation of a mixture of sulfur and mercury.

Research concerning the manufacture of the vermilion of Synthèse developed much XVIIIe at the 19th century. Indeed, at that time, the Dutchmen jealously kept secret their manufacturing processes. English vermilion had a very bad reputation since its color deteriorated quickly. The natural pigment ceases being marketed at the 19th century. In Europe, the manufactoring process of vermilion by wet process starts to be used in Germany at the 18th century. At the beginning of the 20th century, vermilion is replaced by the reds of Cadmium.

When exactly the synthetic Cinabre or vermilion was invented? The documents miss or are often vague. However, the Chinese, can be the first to have discovered how to manufacture vermilion by Dry roads at the beginning of our era and they would be then Arabic who would have brought this method in Occident. However, a certain tradition wants that it is Zosime de Panapolis, scientist and Alchimiste Greek, born has Panapolis in Egypt which at the 3rd century of our era for the first time would have mentioned in its writing or discovered that cinnabar was composed of sulfur and mercury.

The Alchimiste Gerber born in Iran at the 8th century would have made make with chemistry advanced spectacular and shown that if cinnabar could be broken up, one could create it by the synthesis of sulfur and mercury or heat could recombine these element in vermilion.

Bibliographical notes and references

Hofer and Rudolf-Meier, 1999: Hofer, Lothar and Rudolf Meier, Johannes. Occupational hazards due to mercury and its compounds, Division Occupational medicine, Suva, Swiss National bank of insurance in the event of accidents, Lucerne, 2nd edition - May 1999, Lucerne, 1999, p. 1-32.

Unknown author: Unknown author. Files of discovered and the new inventions, made in Sciences, Arts and Manufactures, both in France and in the foreign Countries, during the year 1815. Treuttel and Würtz, Paris, 1816.

Baillaud and Al, 2004: Baillaud B., of Gramont J., Hoots D. Medieval Encyclopédies, speech and knowledge. Texts gathered and published by B. Baillaud, J. of Gramont and D. Hüe. University presses of Rennes and Association Diderot. Diderot books, 2004,10, p.67-99.

Brard C.P., 1821: Brard C.P. Minéralogie applied to Arts, or History of the Minerals which are employed in agriculture, the domestic economy, medicine; the manufacture of salts, fuels and metals; architecture and decoration; painting and the drawing; mechanical arts; the jewelry and the jewelry. Divide into volumes second. At F.G. Levrault, Strasbourg, 1821,474p.

Breuer, 2000: Breuer Hams. Atlas of Chemistry. French General bookstore, Italy, 2000. Chapter IV, Group of zinc, 212p.

Cennino Cennini, 1982: Cennino Cennini. The Book of Art, translation of Victor Mottez, F. of Nobelle, Paris, 1982, p.29.

Daniels, 1987: Daniels Vincent. The Blackening off Vermilion by Light. Recent Advances in the Conservation and Analysis off Artefacts. Summer Schools Near, London, 1987, p.280-282.

To crack, 1967: To crack R.L. Studies in the darkening off vermilion by light. Carryforward and studies in the history off Arts. National Gallery off Art, Washington D.C., 1967, p.99-111.

Gettens and Al, 1972: Gettens Rutherford J., To crack Robert L., Drives out W.T. Vermilion and Cinnabar. Studies in Conservation, 1972,17,2, p.45-69.

Grant Edward ED., 1974: Large Edward (ED.). In Source Book in Medieval Science. Harvard University Close Cambridge, Massachusetts, 1974.

Itier, 1848: Itier Jules. Newspaper of a voyage in China in 1843,1844,1845,1846. The second Volume. At Dauvin and Fontaine, Publisher-booksellers, Paris, 1848, p.19-20.

Keune, Boon, 2005: Keune Katrien and Boon Jaap J. Analycal Imaging Studies Clarifying the Process off the Darkening off Vermilion in Paintings. Molecular Painting Research Group, FOM Intitute for Atomic and Molecular Physics, Kruislaan 407,1098 SJ Amsterdam, The Netherlands. Anal. Chem., 2005,77, p.4742.

Lamure and Brusset, 1962: Lamure J and Brusset H. Mercure. In, Pascal Paul (to dir.). New treaty of Inorganic chemistry, Divides into volumes V: Zinc-Cadmium-mercury. Masson and Co, Editors, Paris, 1962, p. 433,733-797

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