Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in group 6, it is a steely-grey, lustrous and brittle transition metal. Chromium boasts a high usage rate as a metal, able to be polished while resisting tarnishing. Chromium is the main additive in stainless steel, a popular steel alloy due to its uncommonly high specular reflection. Simple polished chromium reflects 70% of the visible spectrum, with 90% of infrared light being reflected; the name of the element is derived from the Greek word χρῶμα, chrōma, meaning color, because many chromium compounds are intensely colored. Ferrochromium alloy is commercially produced from chromite by silicothermic or aluminothermic reactions and chromium metal by roasting and leaching processes followed by reduction with carbon and aluminium. Chromium metal is of high value for hardness. A major development in steel production was the discovery that steel could be made resistant to corrosion and discoloration by adding metallic chromium to form stainless steel.
Stainless steel and chrome plating together comprise 85% of the commercial use. In the United States, trivalent chromium ion is considered an essential nutrient in humans for insulin and lipid metabolism. However, in 2014, the European Food Safety Authority, acting for the European Union, concluded that there was not sufficient evidence for chromium to be recognized as essential. While chromium metal and Cr ions are not considered toxic, hexavalent chromium is both toxic and carcinogenic. Abandoned chromium production sites require environmental cleanup. Chromium is the fourth transition metal found on the periodic table, has an electron configuration of 3d5 4s1, it is the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. This occurs again in the periodic table with other elements and their electron configurations, such as copper and molybdenum; this occurs. In the previous elements, the energetic cost of promoting an electron to the next higher energy level is too great to compensate for that released by lessening inter-electronic repulsion.
However, in the 3d transition metals, the energy gap between the 3d and the next-higher 4s subshell is small, because the 3d subshell is more compact than the 4s subshell, inter-electron repulsion is smaller between 4s electrons than between 3d electrons. This lowers the energetic cost of promotion and increases the energy released by it, so that the promotion becomes energetically feasible and one or two electrons are always promoted to the 4s subshell. Chromium is the first element in the 3d series where the 3d electrons start to sink into the inert core. Chromium is a strong oxidising agent in contrast to the tungsten oxides. Chromium is hard, is the third hardest element behind carbon and boron, its Mohs hardness is 8.5, which means that it can scratch samples of quartz and topaz, but can be scratched by corundum. Chromium is resistant to tarnishing, which makes it useful as a metal that preserves its outermost layer from corroding, unlike other metals such as copper and aluminium. Chromium has a melting point of 1907 °C, low compared to the majority of transition metals.
However, it still has the second highest melting point out of all the Period 4 elements, being topped by vanadium by 3 °C at 1910 °C. The boiling point of 2671 °C, however, is comparatively lower, having the third lowest boiling point out of the Period 4 transition metals alone behind manganese and zinc. Chromium has an unusually high specular reflection in comparison to that of other transition metals. At 425 μm, chromium was found to have a relative maximum reflection of about 72% reflectance, before entering a depression in reflectivity, reaching a minimum of 62% reflectance at 750 μm before rising again to reflecting 90% of 4000 μm of infrared waves.. When chromium is formed into a stainless steel alloy and polished, the specular reflection decreases with the inclusion of additional metals, yet is still rather high in comparison with other alloys. Between 40% and 60% of the visible spectrum is reflected from polished stainless steel; the explanation on why chromium displays such a high turnout of reflected photon waves in general the 90% of infrared waves that were reflected, can be attributed to chromium's magnetic properties.
Chromium has unique magnetic properties in the sense that chromium is the only elemental solid which shows antiferromagnetic ordering at room temperature. Above 38 °C, its magnetic ordering changes to paramagnetic.. The antiferromagnetic properties, which cause the chromium atoms to temporarily ionize and bond with themselves, are present because the body-centric cubic's magnetic properties are disproportionate to the lattice periodicity; this is due to the fact that the magnetic moments at the cube's corners and the cube centers are not equal, but are still antiparallel. From here, the frequency-dependent relative permittivity of chromium, deriving from Maxwell's equations in conjunction with chromium's antiferromagnetivity, leaves chromium with a high infrared and visible light reflectance. Chromium metal left standing in air is passivated by oxidation, forming a th
Galena called lead glance, is the natural mineral form of lead sulfide. It is an important source of silver. Galena is one of the most abundant and distributed sulfide minerals, it crystallizes in the cubic crystal system showing octahedral forms. It is associated with the minerals sphalerite and fluorite. Galena is the main ore of lead, used since ancient times; because of its somewhat low melting point, it was easy to liberate by smelting. It forms in low-temperature sedimentary deposits. In some deposits the galena contains about 1–2% silver, a byproduct that far outweighs the main lead ore in revenue. In these deposits significant amounts of silver occur as included silver sulfide mineral phases or as limited silver in solid solution within the galena structure; these argentiferous galenas have long been an important ore of silver. Galena deposits are found worldwide in various environments. Noted deposits include those at Freiberg in Saxony. In the United States, it occurs most notably in the Mississippi Valley type deposits of the Lead Belt in southeastern Missouri, in the Driftless Area of Illinois and Wisconsin.
Galena was a major mineral of the zinc-lead mines of the tri-state district around Joplin in southwestern Missouri and the adjoining areas of Kansas and Oklahoma. Galena is an important ore mineral in the silver mining regions of Colorado, Idaho and Montana. Of the latter, the Coeur d'Alene district of northern Idaho was most prominent. Galena is the official state mineral of the U. S. states of Wisconsin. The largest documented crystal of galena is composite cubo-octahedra from the Great Laxey Mine, Isle of Man, measuring 25 cm × 25 cm × 25 cm. Galena belongs to the octahedral sulfide group of minerals that have metal ions in octahedral positions, such as the iron sulfide pyrrhotite and the nickel arsenide niccolite; the galena group is named after its most common member, with other isometric members that include manganese bearing alabandite and niningerite. Divalent lead cations and sulfur anions form a close-packed cubic unit cell much like the mineral halite of the halide mineral group. Zinc, iron, antimony, arsenic and selenium occur in variable amounts in galena.
Selenium substitutes for sulfur in the structure constituting a solid solution series. The lead telluride mineral altaite has the same crystal structure as galena. Within the weathering or oxidation zone galena alters to cerussite. Galena exposed to acid mine drainage can be oxidized to anglesite by occurring bacteria and archaea, in a process similar to bioleaching. One of the oldest uses of galena was in the eye cosmetic kohl. In Ancient Egypt, this was applied around the eyes to reduce the glare of the desert sun and to repel flies, which were a potential source of disease. Galena is the primary ore of lead, used in making lead–acid batteries. Galena is mined for its silver content, such as at the Galena Mine in northern Idaho. Known as "potter's ore", galena is used in a green glaze applied to pottery. Galena is a semiconductor with a small band gap of about 0.4 eV, which found use in early wireless communication systems. It was used as the crystal in crystal radio receivers, in which it was used as a point-contact diode capable of rectifying alternating current to detect the radio signals.
The galena crystal was used with a sharp wire, known as a "cat's whisker" in contact with it. The operation of the radio required that the point of contact on the galena be shifted about to find a part of the crystal that acted as a rectifying diode. Making such wireless receivers was a popular home hobby in Britain and other European countries during the 1930s. Scientists associated with the investigation of the diode effect are Karl Ferdinand Braun and Jagadish Bose. In modern wireless communication systems, galena detectors have been replaced by more reliable semiconductor devices. List of minerals Lead smelter Klein, Cornelis. Manual of Mineralogy. Wiley. Pp. 274–276. ISBN 0-471-80580-7. Case Studies in Environmental Medicine: Lead Toxicity. ToxFAQs: Lead. Mineral Information Institute entry for lead
Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, high strength. Titanium is resistant to corrosion in sea water, aqua regia, chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, was named by Martin Heinrich Klaproth after the Titans of Greek mythology; the element occurs within a number of mineral deposits, principally rutile and ilmenite, which are distributed in the Earth's crust and lithosphere, it is found in all living things, water bodies and soils. The metal is extracted from its principal mineral ores by the Hunter processes; the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include a component of smoke screens and catalysts. Titanium can be alloyed with iron, aluminium and molybdenum, among other elements, to produce strong, lightweight alloys for aerospace, industrial processes, agri-food, medical prostheses, orthopedic implants and endodontic instruments and files, dental implants, sporting goods, mobile phones, other applications.
The two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is less dense. There are two allotropic forms and five occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the same number of valence electrons and are in the same group in the periodic table and zirconium differ in many chemical and physical properties; as a metal, titanium is recognized for its high strength-to-weight ratio. It is a strong metal with low density, quite ductile and metallic-white in color; the high melting point makes it useful as a refractory metal. It is paramagnetic and has low electrical and thermal conductivity. Commercially pure grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, but are less dense. Titanium is 60% denser than aluminium, but more than twice as strong as the most used 6061-T6 aluminium alloy.
Certain titanium alloys achieve tensile strengths of over 1,400 MPa. However, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel. Machining requires precautions, because the material can gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a fatigue limit that guarantees longevity in some applications; the metal is a dimorphic allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases as it is heated to this transition temperature but falls and remains constant for the β form regardless of temperature. Like aluminium and magnesium, titanium metal and its alloys oxidize upon exposure to air. Titanium reacts with oxygen at 1,200 °C in air, at 610 °C in pure oxygen, forming titanium dioxide, it is, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation.
When it first forms, this protective layer continues to grow slowly. Atmospheric passivation gives titanium excellent resistance to corrosion equivalent to platinum. Titanium is capable of withstanding attack by dilute sulfuric and hydrochloric acids, chloride solutions, most organic acids. However, titanium is corroded by concentrated acids; as indicated by its negative redox potential, titanium is thermodynamically a reactive metal that burns in normal atmosphere at lower temperatures than the melting point. Melting is possible only in a vacuum. At 550 °C, it combines with chlorine, it reacts with the other halogens and absorbs hydrogen. Titanium is one of the few elements that burns in pure nitrogen gas, reacting at 800 °C to form titanium nitride, which causes embrittlement; because of its high reactivity with oxygen and some other gases, titanium filaments are applied in titanium sublimation pumps as scavengers for these gases. Such pumps inexpensively and reliably produce low pressures in ultra-high vacuum systems.
Titanium is the ninth-most abundant element in the seventh-most abundant metal. It is present as oxides in most igneous rocks, in sediments derived from them, in living things, natural bodies of water. Of the 801 types of igneous rocks analyzed by the United States Geological Survey, 784 contained titanium, its proportion in soils is 0.5 to 1.5%. Common titanium-containing minerals are anatase, ilmenite, perovskite and titanite. Akaogiite is an rare mineral consisting of titanium dioxide. Of these minerals, only rutile and ilmenite have economic importance, yet they are difficult to find in high concentrations. About 6.0 and 0.7 million tonnes of those minerals were mined in 2011, respectively. Signi
Chalcocite, copper sulfide, is an important copper ore mineral. It is dark-gray to black with a metallic luster, it has a hardness of 2 1⁄2 - 3 on the Mohs scale. It is a sulfide with an orthorhombic crystal system; the term chalcocite comes from the alteration of the obsolete name chalcosine, from the Greek khalkos, meaning copper. It is known as redruthite, vitreous copper and copper-glance. Chalcocite is sometimes found as a primary vein mineral in hydrothermal veins. However, most chalcocite occurs in the supergene enriched environment below the oxidation zone of copper deposits as a result of the leaching of copper from the oxidized minerals, it is often found in sedimentary rocks. It is one of the most profitable copper ores; the reasons for this is its high copper content and the ease at which copper can be separated from sulfur. Since chalcocite is a secondary mineral that forms from the alteration of other minerals, it has been known to form pseudomorphs of many different minerals. A pseudomorph is a mineral that has replaced another mineral atom by atom, but it leaves the original mineral's crystal shape intact.
Chalcocite has been known to form pseudomorphs of the minerals bornite, chalcopyrite, enargite, millerite and sphalerite. Copper sulfide Copper monosulfide Dana's Manual of Mineralogy ISBN 0-471-03288-3 Mineral Galleries
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Nevada. It was the first major discovery of silver ore in the United States, named after American miner Henry Comstock. After the discovery was made public in 1859, it sparked a silver rush of prospectors to the area, scrambling to stake their claims; the discovery caused considerable excitement in California and throughout the United States, the greatest since the California Gold Rush in 1849. Mining camps soon thrived in the vicinity, which became bustling commercial centers, including Virginia City and Gold Hill; the Comstock Lode is notable not just for the immense fortunes it generated and the large role those fortunes had in the growth of Nevada and San Francisco, but for the advances in mining technology that it spurred, such as square set timbering and the Washoe process for extracting silver from ore. The mines declined after 1874. Volcanic vents to the east covered the area during the Tertiary, a fault fissure opened the east slope of the Virginia Range.
The east slope of the range forms the footwall of the Lode, is composed of diorite, while the hanging wall is composed of andesite, which the miners called "porphyry". The fault fissures filled these fissures with "mineral-bearing quartz"; the miners stated "porphyry makes ore". The ore bodies were thinly scattered through the wide Lode'like plums in a charity pudding', nearly all of them were found in the wide upper section and along or near the east wall. Although the miners extended their work in all directions, only "sixteen large and rich ore bodies" were found, most less than 600 feet in depth. Six major bonanzas marked the first five years of the Comstock Lode; the Ophir bonanza was prosperous until 1864. Though rich, having a length of 500 feet at the surface, the ore body wedged out at a depth of 500 feet; the Gold & Curry bonanza included 500 feet of the El Dorado outcrop, but dipped southward into the Savage at 500 feet. The Savage bonanza included this ore body and a second bonanza, an ore body shared with Hale & Norcross to the south, at the 600 foot level.
The Chollar-Potosi bonanza was consolidated in 1865. The 1875 Combination Shaft was a joint effort by Hale & Norcross; the Original Gold Hill bonanza consisted of the Old Red Ledge, 1,000 feet long, 500 feet wide, 500 feet deep. The associated Gold Hill mines were merged into the Consolidated Imperial by 1876; the Yellow Jacket shared the Gold Hill bonanza on its north, shared a second bonanza with Crown Point and Kentuck to the south, discovered in 1864. The Crown Point-Belcher bonanza was discovered in 1870; the ore body extended from the 900 to the 1,500-foot level, having a length of 775 feet and a width of 120 feet. The ore, the precious metal value of, 54 percent from gold and 46 percent from silver, lasted only four years; the Consolidated Virginia bonanza was discovered at the 1,200-foot level in March 1873. The ore body terminated at the 1650-foot level. Gold was found in this region in the spring of 1850, in Gold Canyon, by a company of Mormon emigrants, one of whom, Abner Blackburn, was their guide.
After arriving much too early to cross the Sierra, the wagon train camped on the Carson River in the vicinity of Dayton, to wait for the mountain snow to melt. William Prouse soon found gold along the gravel river banks by panning, but left when the mountains were passable, as they anticipated taking out more gold on reaching California. Orr named the gulch Gold Cañón. Other emigrants camped in the canyon and went to work at mining. However, when the supply of water in the canyon gave out toward the end of summer, they continued across the mountains to California; the camp had no permanent population until the winter and spring of 1852–53, when about 100 men worked part of the year along the gravel banks of the canyon with rockers, Long Toms and sluices. After nine years, the Gold Canyon placers were producing less, many miners left for the Mono Lake placers; the gold from Gold Canyon came from quartz veins, toward the head of the vein, in the vicinity of where Silver City and Gold Hill now stand.
As the miners worked their way up the stream, they founded the town of Johntown on a plateau. In 1857, the Johntown miners found gold in Six-Mile Canyon, about five miles north of Gold Canyon; the heads of both these canyons form the north and south ends of what is now known as the Comstock Lode, defined by the Ophir Discovery and the Gold Hill Discovery. The early placer miners never worked out the location of the placer gold, since the Lode surface structure was "largely worn away and covered with debris from the mountain sides above." Credit for the discovery of the Comstock Lode is disputed. It is said to have been discovered, in 1857, by Ethan Allen Grosh and Hosea Ballou Grosh, sons of a Pennsylvania clergyman, trained mineralogists and veterans of the California gold fields. Hosea injured his foot and died of septicemia in 1857. In an effort to raise funds, accompanied by an associate Richard Maurice Bucke, set out on a trek to California with samples and maps of his claim. Henry Comstock was left in their stead to care for the Grosh cabin and a locked chest containing silver and gold ore samples and documents of the discovery.
Grosh and Bucke never made it to California, getting lost and suffering severe hardship while crossing the Sierra Nevada mountains. The two suffered from frostbite while crossing the Sierras, at the hands of a minor surgeon lost li
Niobium known as columbium, is a chemical element with symbol Nb and atomic number 41. It is a soft, crystalline, ductile transition metal found in the minerals pyrochlore and columbite, hence the former name "columbium", its name comes from Greek mythology Niobe, the daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, making them difficult to distinguish; the English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, the English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical; the German chemist Heinrich Rose determined in 1846 that tantalum ores contain a second element, which he named niobium. In 1864 and 1865, a series of scientific findings clarified that niobium and columbium were the same element, for a century both names were used interchangeably. Niobium was adopted as the name of the element in 1949, but the name columbium remains in current use in metallurgy in the United States.
It was not until the early 20th century. Brazil is the leading producer of an alloy of 60 -- 70 % niobium with iron. Niobium is used in alloys, the largest part in special steel such as that used in gas pipelines. Although these alloys contain a maximum of 0.1%, the small percentage of niobium enhances the strength of the steel. The temperature stability of niobium-containing superalloys is important for its use in jet and rocket engines. Niobium is used in various superconducting materials; these superconducting alloys containing titanium and tin, are used in the superconducting magnets of MRI scanners. Other applications of niobium include welding, nuclear industries, optics and jewelry. In the last two applications, the low toxicity and iridescence produced by anodization are desired properties. Niobium is considered a technology-critical element. Niobium was identified by English chemist Charles Hatchett in 1801, he found a new element in a mineral sample, sent to England from Connecticut, United States in 1734 by John Winthrop F.
R. S. and named the mineral columbite and the new element columbium after Columbia, the poetical name for the United States. The columbium discovered by Hatchett was a mixture of the new element with tantalum. Subsequently, there was considerable confusion over the difference between columbium and the related tantalum. In 1809, English chemist William Hyde Wollaston compared the oxides derived from both columbium—columbite, with a density 5.918 g/cm3, tantalum—tantalite, with a density over 8 g/cm3, concluded that the two oxides, despite the significant difference in density, were identical. This conclusion was disputed in 1846 by German chemist Heinrich Rose, who argued that there were two different elements in the tantalite sample, named them after children of Tantalus: niobium and pelopium; this confusion arose from the minimal observed differences between niobium. The claimed new elements pelopium and dianium were in fact identical to niobium or mixtures of niobium and tantalum; the differences between tantalum and niobium were unequivocally demonstrated in 1864 by Christian Wilhelm Blomstrand and Henri Etienne Sainte-Claire Deville, as well as Louis J. Troost, who determined the formulas of some of the compounds in 1865 and by Swiss chemist Jean Charles Galissard de Marignac in 1866, who all proved that there were only two elements.
Articles on ilmenium continued to appear until 1871. De Marignac was the first to prepare the metal in 1864, when he reduced niobium chloride by heating it in an atmosphere of hydrogen. Although de Marignac was able to produce tantalum-free niobium on a larger scale by 1866, it was not until the early 20th century that niobium was used in incandescent lamp filaments, the first commercial application; this use became obsolete through the replacement of niobium with tungsten, which has a higher melting point. That niobium improves the strength of steel was first discovered in the 1920s, this application remains its predominant use. In 1961, the American physicist Eugene Kunzler and coworkers at Bell Labs discovered that niobium-tin continues to exhibit superconductivity in the presence of strong electric currents and magnetic fields, making it the first material to support the high currents and fields necessary for useful high-power magnets and electrical power machinery; this discovery enabled — two decades — the production of long multi-strand cables wound into coils to create large, powerful electromagnets for rotating machinery, particle accelerators, particle detectors.
Columbium was the name bestowed by Hatchett upon his discovery of the metal in 1801. The name reflected; this name remained in use in American journals—the last paper published by American Chemical Society with columbium in its title dates from 1953—while niobium was used in Europe. To end this confusion, the name niobium was chosen for element 41 at the 15th Conference of the Union of Chemistry in Amsterdam in 1949. A year this name was adopted by the International Union of Pure and Applied Chemistry after 100 years of controversy, despite the chronological precedence of the name columbium; this was a compromise of sorts.
Cinnabar and cinnabarite deriving from the Ancient Greek: κιννάβαρι, refer to the common bright scarlet to brick-red form of mercury sulfide, the most common source ore for refining elemental mercury, is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments. Cinnabar occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs; the mineral resembles quartz in its exhibiting birefringence. The color and properties derive from a structure, a hexagonal crystalline lattice belonging to the trigonal 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, 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, recognized as early as ancient Rome.
The name comes from Ancient Greek: κιννάβαρι, a Greek word most applied by Theophrastus to several distinct substances. Other sources say the word comes from the Persian: a word of uncertain origin. In Latin, it was sometimes known as minium, meaning "red cinnamon", though both of these terms now refer to lead tetroxide. Cinnabar is found in a massive, granular or earthy form and is bright scarlet to brick-red in color, though it occurs in crystals with a nonmetallic adamantine luster, it resembles quartz in its symmetry. It exhibits birefringence, it has the highest refractive index of any mineral, its mean refractive index is 3.08, versus the indices for diamond and the non-mineral gallium arsenide, which are 2.42 and 3.93, respectively. The hardness of cinnabar is 2.0–2.5 on the Mohs scale, its specific gravity 8.1. Structurally, cinnabar belongs to the trigonal crystal system, it occurs as granular to massive incrustations. Crystal twinning occurs as simple contact twins. Note, mercury sulfide, HgS, adopts the cinnabar structure described, one additional structure, i.e. it is dimorphous.
Cinnabar is the more stable form, is a structure akin to that of HgO: each Hg center has two short Hg−S bonds, four longer Hg···S contacts. In addition, HgS is found in a non-cinnabar polymorph that has the zincblende structure. Cinnabar occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs. Cinnabar is deposited by epithermal ascending aqueous solutions far removed from their igneous source, it is associated with native mercury, realgar, marcasite, quartz, dolomite and barite. Cinnabar is found in all mineral extraction localities that yield mercury, notably Almadén; this mine was exploited from Roman times until 1991, being for centuries the most important cinnabar deposit in the world. Good cinnabar crystals have been found there.. Appear in Puerto Princesa, it was mined near Red Devil, Alaska on the middle Kuskokwim River. Red Devil was named after 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 at the present day, such as from the hot waters of Sulphur Bank Mine in California and Steamboat Springs, Nevada. As the most common source of mercury in nature, cinnabar has been mined for thousands of years as far back as the Neolithic Age. During the Roman Empire it was mined both as a pigment, for its mercury content. To produce liquid mercury, crushed cinnabar ore is roasted in rotary furnaces. Pure mercury separates from sulfur in this process and evaporates. A condensing column is used to collect the liquid metal, most shipped in iron flasks. Associated modern precautions for use and handling of cinnabar arise from the toxicity of the mercury component, 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 used cinnabar for art, or processed it into refined mercury "the toxic properties of mercury were well known, it was dangerous to those who mined and processed cinnabar, it caused shaking, loss of sense, death.
Data suggest that mercury was retorted from cinnabar and the workers were exposed to the toxic mercury fumes." Overexposure to mercury, was seen as an occupational disease to the ancient Romans: "Mining in the Spanish cinnabar mines of Almadén, 225 km southwest of Madrid, was regarded as being akin to a death sentence due to the shortened life expectancy of the miners, who were slave