Cinnabar, refer to the common bright scarlet to brick-red form of mercury(II) sulfide, formula HgS, that is the most common source ore for refining elemental mercury, and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Cinnabar generally occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs. The mineral resembles quartz in symmetry and in its exhibiting birefringence; cinnabar has a mean refractive index of ~3.2, a hardness between 2 and 2.5, and a specific gravity of ~8.1. The color and properties derive from a structure that is a rhombohedral crystalline lattice belonging to the hexagonal crystal system, crystals that sometimes exhibit twinning.
Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, in the New World since the Olmec culture, and in China since as early as the Yangshao culture, where it was used in coloring stoneware.
Associated modern precautions for use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as ancient Rome.
Properties and structure
Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color, though it occasionally occurs in crystals with a non-metallic adamantine luster. It resembles quartz in its symmetry. It exhibits birefringence, and it has the highest refractive index of any mineral. Its mean refractive index is 3.08 (sodium light wavelengths), versus the indices for diamond and the non-mineral gallium(III) arsenide (GaAs), which are 2.42 and 3.93, respectively. The hardness of cinnabar is 2.0–2.5 on the Mohs scale, and its specific gravity 8.1.
Structurally, cinnabar belongs to the trigonal crystal system. It occurs as thick tabular or slender prismatic crystals or as granular to massive incrustations. Crystal twinning occurs as simple contact twins.
Note, mercury(II) sulfide, HgS, adopts the cinnabar structure described, and one additional structure, i.e. it is dimorphous. Cinnabar is the more stable form, and is a structure akin to that of HgO: each Hg center has two short Hg-S bonds (each 2.36 Å), and four longer Hg•••S contacts (with 3.10, 3.10, 3.30, and 3.30 Å separations). In addition, HgS is found in a black, non-cinnabar polymorph (metacinnabar) that has the zincblende structure.
Criteria for identification
The color of the mineral trace can also be used for the rough identification of pigments. It involves making a trace of the mineral by friction on a hard porcelain tablet and observing its color. Many minerals have a colorless trace, some have characteristic color traces. Here is an example: The pink to red-brown traces may indicate the presence of cinnabar, cuprite or hematite.
Mercury in small amounts can be detected by spectrometry or by precipitates of Hg₂Cl₂ and HgS. It is considered that if mercury compounds are heated in a tube with soda, there is the formation of a gray mirror of mercury which condenses on the cold walls.
Spectrometric methods allow the identification of cinnabar. It is useful to mention Raman spectroscopy, an optical method, which analyzes contactless (semi) precious stones, pigments, glasses and ceramics. This method does not require sampling. And thanks to their built-in laser source, the latest generation of spectrometers can be transported to the heart of museums. The identification of objects can be done in-situ. In addition, this molecular identification makes it possible to unambiguously differentiate nearby compounds of the same elemental composition.
To identify the crystal structure, the PIXE (Particle Induced X-ray Emission) nuclear probe distinguishes between hexagonal and cubic forms.
Polymorphism of HgS
HgS has a polymorphism:
α-HgS, cinnabar / vermilion
α’-HgS, amorphous mercury sulphide
β-HgS, metacinabrium (black)
The chemical properties of black sulphide and red sulphide of mercury are substantially the same, however, black sulphide reacts more than red. Cinnabar, vermilion or metacinabri are generally considered almost insoluble in water, organic solvents and diluted mineral acids.
The darkening of the scarlet cinnabar color (α-HgS) under the influence of solar irradiation until it becomes gray-black is an important problem in the conservation of wall paintings since antiquity and still represents a breakage. head-generator of polemics. Vitruvius explains that: “When employed in flats whose plaster is covered, the cinnabar retains its color without alteration; but in the places exposed to the air, like the peristyles, the exedra, and some other similar places where the rays of the sun and the brightness of the moon can penetrate, it is altered, it loses the liveliness of its color, it darkens as soon as it is struck by it. The latter mentions that Punic wax was applied to the murals to prevent the light of the moon and the sun’s rays from removing its color; but some associated factors accelerate this chromatic change, such as high humidity associated with a highly polluted atmosphere. Only the surface is degraded, if it is scraped, we can see again the color red. This specific degradation to red cinnabar can also allow its identification.
Currently, the blackening of the frescoes of the Villa of Mysteries in Pompeii is the perfect illustration. Laser cleaning of wall paintings containing cinnabar is not recommended due to the resulting chromatic alteration.
Cinnabar structure, α-HgS (mercury Hg in gray, sulfur S in yellow)
The following formula gives an approximation of the saturated vapor pressure of cinnabar:
ln P * = 8.765 – 3533 / T
P * being expressed in kilopascals and temperature T in Kelvin.
Mercury sulphide HgS is the most important mercury ore. It is used for the manufacture of mercury and as a pigment. Cinnabar contains approximately 86.2% mercury. Mercury is obtained by roasting cinnabar. For the extraction of the metal, the pulverized ore goes down in an oven at 700 ° C where air is sent. The following reaction occurs:
HgS + O2 → Hg + SO2,
above 737 ° C, cinnabar decomposes
HgS → Hg + S.
Mercury is obtained by pyrometallurgy: at atmospheric pressure, cinnabar sublimates at 583 ° C (856 K) and decomposes into liquid mercury and sulfur vapor.
There are three crystalline forms:
the red trigonal cinnabar, space group P3121 or P3221 (No 154), structure B9 in Strukturbericht notation, more stable at temperatures of less than 350 ° C (Barnett et al., 2001: 1499);
the cubic metacinabre, space group F43m, of black color;
Hypercabiner (γ-HgS), revealed by Potter and Barnes in 1978. Its name is linked to the fact that its stability zone extends to higher temperatures than those of cinnabar and metacinabrium.
Cinnabar has been known and used since the earliest antiquity in medicine (Pliny the Elder, Histoire naturelle, XXXIII, p.41, which, moreover, discouraged and regarded this substance as a poison).
It has also been used in medicine for the treatment of syphilis, or it was prescribed in the 1820s to pregnant women by fumigation (General Archives of Medicine, De Vaugirard, 1914, 436.). In the form of an ointment, it was used against cutaneous diseases (Louis Mialhe, Treatise on the Art of Formulation, Ed Fortin, Masson, 1845, 150.).
Cinnabar is also found in the composition of remedies for the external treatment of cancer, such as the paste invented by the surgeon Jean Baseilhac, known as “Brother Como’s powder”, composed of white arsenic, burnt ash from shoe soles, dragon-blood, cinnabar and water (Hermann Lebert, A Practical Treatise on Cancer Diseases and Curable Conditions Combined with Cancer, Baillière, 1851, 645). The use of this arsenic paste will also be advocated by the surgeon Joseph Souberbielle, (nephew of Jean Baseilhac), in the treatment of facial ulcers.
Chinese patent medicines containing cinnabar include: 金、二十五味松石丸、二十五味珊瑚丸、十香返生丸、七珍丸（丹）、七厘散、万氏牛黄清心丸、小儿百寿丸、小儿至宝丸、小儿金丹片、小儿惊风散、小儿清热片、天王补心丸、牙痛一粒丸、牛黄千金散、牛黄抱龙丸、牛黄清心丸、牛黄镇惊丸、安宫牛黄丸、安宫牛黄散、红灵散、苏合香丸、医痫丸、补肾益脑片、局方至宝散、纯阳正气丸、抱龙丸、柏子养心丸、胃肠安丸、香苏正胃丸、保赤散、益元散、梅花点舌丸、琥珀抱龙丸、紫金锭、紫雪、暑症片、舒肝丸、痧药、避瘟散、人参再造丸、平肝舒络丸、再造丸、复方芦荟胶囊、赛霉安散/软膏。
Associated modern precautions for use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as in ancient Rome. Because of its mercury content, cinnabar can be toxic to human beings. Though people in ancient South America often used cinnabar for art, or processed it into refined mercury (as a means to gild silver and gold to objects) “the toxic properties of mercury were well known. It was dangerous to those who mined and processed cinnabar, it caused shaking, loss of sense, and death. Data suggest that mercury was retorted from cinnabar and the workers were exposed to the toxic mercury fumes.” Overexposure to mercury, mercurialism, was seen as an occupational disease to the ancient Romans: “Mining in the Spanish cinnabar mines of Almadén, 225 km (140 mi) southwest of Madrid, was regarded as being akin to a death sentence due to the shortened life expectancy of the miners, who were slaves or convicts.”
The Chinese Taoists used it as a drug of immortality, hence mercurial poisonings. The most famous is that of the first emperor Qin Shi Huang in 210 BC. BC 8.
Since cinnabar is powdery or in the form of powder, strict protection measures are strongly recommended.
Cinnabar generally occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs. Cinnabar is deposited by epithermal ascending aqueous solutions (those near surface and not too hot) far removed from their igneous source. It is associated with native mercury, stibnite, realgar, pyrite, marcasite, opal, quartz, chalcedony, dolomite, calcite and barite.
Cinnabar is essentially found in all mineral extraction localities that yield mercury, notably Almadén (Spain); Puerto Princesa (Philippines); New Almaden (California); Hastings Mine and St. John’s Mine, Vallejo, California;[page needed][better source needed] Idrija (Slovenia); New Idria (California); Giza, Egypt; Moschellandsberg (de) near Obermoschel in the Palatinate; La Ripa, at the foot of the Apuan Alps and in the Mount Amiata (both in Tuscany); the mountain Avala (Serbia); Huancavelica (Peru); Murfreesboro, Arkansas; Terlingua, Texas (United States); and the province of Guizhou in China, where fine crystals have been obtained. It was also mined near Red Devil, Alaska on the middle Kuskokwim River. Red Devil was named after the Red Devil cinnabar mine, a primary source of mercury. It has been found in Dominica near its sulfur springs at the southern end of the island along the west coast.
Cinnabar is still being deposited, e.g, at the present day from the hot waters of Sulphur Bank Mine in California and Steamboat Springs, Nevada.
Mining and extraction of mercury:
As the most common source of mercury in nature, cinnabar has been mined for thousands of years, even as far back as the Neolithic Age. During the Roman Empire it was mined both as a pigment, and for its mercury content.:XLI
To produce liquid mercury (quicksilver), crushed cinnabar ore is roasted in rotary furnaces. Pure mercury separates from sulfur in this process and easily evaporates. A condensing column is used to collect the liquid metal, which is most often shipped in iron flasks.
Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, in the New World since the Olmec culture, and in China since as early as the Song dynasty, where it was used in coloring lacquerware.
Cinnabar’s use as a color in the New World, since the Olmec culture, is exemplified by its use in royal burial chambers during the peak of Maya civilization, most dramatically in the Tomb of the Red Queen in Palenque (600–700 AD), where the remains of a noble woman and objects belonging to her in her sarcophagus were completely covered with bright red powder made from cinnabar.
The most popularly known use of cinnabar is in Chinese carved lacquerware, a technique that apparently originated in the Song dynasty. The danger of mercury poisoning may be reduced in ancient lacquerware by entraining the powdered pigment in lacquer, but could still pose an environmental hazard if the pieces were accidentally destroyed. In the modern jewelry industry, the toxic pigment is replaced by a resin-based polymer that approximates the appearance of pigmented lacquer.
Cinnabar is used as a pigment to make ceramics, mural frescoes and during religious ceremonies, from the Neolithic period. The oldest archaeological evidence 13 can be found in Turkey (Çatalhöyük, -7000, -8000), in Spain (Casa Montero mine and tombs of La Pijota and Montelirio, -5300) and in China (Yangshao culture -4000, -3500 and beginning of the Bronze Age in the culture of Erlitou)
The Chinese used cinnabar 3,600 years ago as a pigment for pottery or ink. They would have been the first to have made vermilion at the beginning of our era. In the Egypt of the Ptolemies (fourth centuries), the practice of cremation appears. On some fragments of burned bone, there is a red color, the dye is cinnabar intentionally deposited.
Around 300 BC Theophrastus, philosopher and Greek scholar, evokes in the Book of Stones4 the cinnabar mines of Almaden in Spain, in Colchis and near Ephesus where cinnabar is extracted from a sandy mineral.
The mines of Mount Amiata in Italy also known since ancient times.
In the first century, Dioscorides devotes a record of his pharmacopoeia, ” Materia medica” (V, 94), cinnabar from Libya and used in pharmacology and painting, and the record V, 95 mercury (” hydrargyros ” ὑδραργυρος) which he indicates the extraction process:
“… we put on a bowl of clay an iron shell containing cinnabar, we add an ” ambix ” [cut back], we play with clay, then we warm it with coals. Steam that adheres to the ‘ambix’, once scraped, becomes mercury ‘(Mertens, 17).
This description of a device used to make sublimations is the ancestor of the stills. The borrowing of the Greek term ambix in Arabic will give al-‘anbīq (with the pronoun) which after passing through medieval Latin will give in French “still”.
Cinnabar was used in antiquity as a pigment that was generally reserved for the elite. Thus, Rome makes it a state monopoly and a law fixes the selling price. Pliny mentions it under the name of minium in books XXXIII and XXXV of his Histoire Naturelle. Vitruvius (De Architectura, VII), in the first century BC J.-C., describes the use of cinnabar in painting. Zosimus of Panopolis, scholar and Greek alchemist, born in Egypt, would have, in the third century of our era, mentioned that cinnabar was composed of mercury and sulfur. The alchemist Geber or Jabir Ibn Hayyan, born in Iran in 721, explains that mercury and sulfur can, with heat combine in cinnabar.
In the Middle Ages, in the East, the most important documents were signed with a cinnabar ink (in Byzantium, the emperor alone could use it) while in the West (some sources evoke the thirteenth century, others xiie) some illuminations were made using a cinnabar and blood ink. The artists of the time were careful to isolate this substance too reactive to other pigments with varnish and protect it from the sun by posing over glazes (madder). Medieval recipes evoke the addition of cerumen, because this wax has fungicidal properties. The monk Theophilus, in the twelfth century, explains that the mixture of equal parts of sulfur and mercury was arranged in a glass container closed with clay which was heated until the formation of the pigment. Cennino Cennini, circa 1390, in his book of art, also mentions this pigment.
The vein of Idrija, in present-day Slovenia, is discovered in 1490. Huancavelica, Peru, is discovered in 1564. At the beginning of the sixteenth century, the Idrija mine developed under the control of the Republic of Venice, which markets , mercury everywhere in Central Europe, the Eastern Mediterranean and Flanders. The powerful Fugger commercial dynasty, from southern Germany, is gaining a dominant position in non-ferrous metal mines in Europe, thanks to an agreement with the ruling house of the Habsburgs. Almadén was part of this entity, and the extraction of mercury is relaunched there in about 1550. The reason for this is the extraction of precious metals from deposits in South America and Central America, which were among the main motivations for Spanish colonial expansion. An initial amalgamation test for silver mining is probably carried out in Venice in 1507. While the exploitation in the Andes took advantage of the discovery of mercury deposits in Huancavelica, New Spain had to import massively mercury from European mines18. The Mercury Heritage. Almadén and Idrija reports on the important contribution to the history of humanity that the two sites have had.
In 1527, Paracelsus prescribed mercury and its oxide as medicine in ointments as a remedy for syphilis.
In 1797, Constantin Kirchhoff discovered a process for the production of cinnabar (mercury sulphide) by the wet method.