Cobalt: Cornerstone of Society?By Mallory Woodard
Throughout the ancient periods of the Egyptian and Mesopotamian empires to the modern day, Cobalt has been an extremely influential element on both the human progress in technology and what today is modern society. In the eras of past civilization when trading and crafts, such as pottery (and later, glassblowing) and trade began to emerge, this elemental byproduct often brought great wealth and, to the suppliers of this substance, great power and prestige. At a time, in some cultures, it was believed to have been the fuel of hell’s blaze in the underworld due to it’s high flammability and the menacing blue tint it gave off into the flames. In other cultures, it was believed to have been an essence meant only for Gods and their chosen nobility on Earth. Because of this, cobalt was almost as priceless as gold. Eventually, time passed and these outrageous beliefs expired, but that did not end the curious attention it drew even centuries later. In the early 18th century (1735), a man named Georg Brandt, a Swedish chemist and renowned scientist, proclaimed it an element after much experimentation. In this period of time, Cobalt had very often been mistaken for Bismuth, an element in appearance and composure very similar to Cobalt. However, Brandt found that these two elements were found in much different parts of the world and were found in different materials. Bismuth was an earthy element which could have only been found in the earth’s crust. Cobalt on the other hand, along with its shared destination in the earth, could also have been found in the foods they ate and the grass their livestock grazed upon. In addition to that, though their blue-ish light spectra were similar, they were varied in their flammability and elemental composition. He also argued that the blue color of many burning gases was because of this element and not Bismuth. This element, as could be found later, was also present in meteorites and was an essential component to all life.
It was not always called Cobalt. During the time of George Brandt in Sweden, Cobalt was referred to as “Kobald”, meaning “goblin” or “evil spirit”. Perhaps some of the earlier civilization’s interpretations of this element carried on to the later eras. It was a lustrous, metallic matter with a sort of grey-ish, lead-like tinge, much resembling the color of ash. This observation may have contributed to it’s relation to hell, or underworld. At the time, there were several cultures that believed of a life after death, regardless of one’s good deeds in their lifetime, consisting of eternal gloom and depression. In the epic story of Giglamesh, the King Giglamesh speaks to his seriously ill friend, Inkidu, about a dream he had dreamt of. Inkidu describes a gray place of “dirt and ash”, where kings and peasants alike resided in gloom. Although this epic had been written centuries before the time of our Swedish chemist, the ideal still held true to many people outside of the reaches of the Scientific Revolution that took place but a few centuries prior. With this idea matching the influence created around the image of Cobalt, as well as the older experimentations with the element, it was considered an “evil” compound of some sort, and thus there was no real encouragement to find a purpose for it.
The element is, interestingly enough, also found in the crust of meteorites. This discovery has helped mankind to assume that if there are similar elements in meteorites to it’s own on Earth, that there may be other planets like Earth capable of supporting life. In addition to this, several previously unknown isotopes and ores of this element had been discovered in the recent 20th century. It’s been proven many of these have contributed to or possessed the essence of several modern-day and ancient achievements. For example, blue glass, electroplating and a source for radioactive y-rays. When glassblowing has become more affordable with the invention of new glassmaking techniques, pigments were often added to distinguish between “common” glass and “nobility” glass. A popular pigment was blue, which was supplied by the Cobalt ore, Cobaltite (CoAsS). The growing demand for this dark and light blue glass encouraged economic commerce in whatever areas in Europe they were supplied (now mined in Canada, Morocco, and Zaire), thus encouraging the practice of early industry and bulk manufacture. As for a more recent use of one of Cobalt’s isotopes, it often made the difference between life and death. The Cobalt isotope Cobalt -60 (60Co) is an artificially produced substance with a half-life of 5.27 years which, like Uranium or any other radioactive solid, releases semi-focused y-rays/gamma rays. It is useful in the medical field of cancer treatment, but it tends to only be used on especially risky patients—risky being defined in this case as for whatever reason not being able to receive the traditional, stronger radiation treatment. Cobalt is a substance found naturally in the human body, so the treatment is a bit more lenient on the body while still succeeding in destroying in cancer cells. Although not as effective as the traditional treatment, it is a softer alternate for young children and sickly elders. This substance can be bought as well, but only (for health precaution) to scientific or authorized medical facilities. For a single compact sources of Cobalt-60, prices vary from one to ten dollars, or curie (The previous eastern European currency in countries such as Germany and Austria), depending on quality and activity. Other ores and isotopes, miscellaneous in their use, consist of Cobalt-56, Cobalt -57, Cobalt-58, Cobalt-59, and Cobalt-61 as well as many different arsenites, sulphites, and specific ores such as erythrite Co3(AsO4)2 and cobaltite CoAsS. The actual element itself, because of it’s hard brittle texture and magnetic properties, is more often then not simply used as magnets or radioactive tracers. In the instance of electroplating, which is the process of giving a metal a shining surface, it helps to reduce if not prevent oxidation and widely used for alloys. Through beta-decay, it dissolves into nickel-60.
Cobalt is found in the presence of many other minerals and elements when mined from the earth. When mining for copper, nickel and lead, Cobalt emerges as a common byproduct of the raw materials. It is produced as the hydroxide of that particular element by precipitation with sodium hypochloride. In addition to this, it can also be obtained from the chemical compounds of arsenic, sulfer, oxygen and cobaltine. This trace of sodium in every form of Cobalt and it’s familiars create types of Cobalt salts. As previously stated, Cobalt is found in the ground and thus, in the plant life that grows from it. Thus, it developed into an essential essence to many life forms. It is known to also be the core of the vitamin B12, a common vitamin found in fruits, leafy vegetables and herbs and essential for the grass-grazers’ circulatory and digestive systems to function properly. Soil(s) should contain 0.13 to 0.30 ppm of Cobalt for proper animal nutrition. For humans however, the intake of cobalt is regulated by the Recommended Daily Allowance (RDA), though it is encouraged to avoid deficiency as much as possible by eating plenty of pulps and leafy vegetables. Although if too much cobalt is indulged, heart muscles may be damaged and the over-production of red blood cells may damage the artery and vein walls of your circulatory system. Like Iron, cobalt must be taken in accordance to a nutritional, healthy diet to avoid anemia and encourage the production of healthy blood cells and white cells.
It has also been suggested and proven that Cobalt is not a very reactive element, despite it’s flammability. It’s not reactive with air and has little reaction with water (cold or warm water), it has no reactivity outside it’s isotope Cobalt-60 (described on a previous page) and has no distinct odor, nor does it have any sort of reaction with Nitrogen. It does, however, have considerable reactions to high heat. When heated over the considerable temperature of a Bunsen Burner, the compound Co3O4 is formed. When further heated (over a searing 900 degrees Celsius), Cobalt (II) oxide is formed, or CoO. It has a docile effect when placed in acid, but not anything particularly out of the ordinary in comparison to the effects of any other substance. Exposure should be limited, though it has no radioactivity, because the dust and residue is known to be poisonous and toxic to the body. By regulation, one should be limited to 0.05mg/m^3 (8-hour time-weighted average by 40-hours a week).
Many names have been given to distinguish the attractive blue line spectrum that Cobalt released when ignited. Some of these names include “Cobalt bloom” for Erythrite, “Cobalt Ultramarine” and “Thenard’s blue”, named after the man who discovered the actual wavelength of Cobalt’s blue and distinguished it’s difference to a normal pigment of blue. Evidently, while the normal pigment was a consistent wavelength, “Thenard’s blue” or Cobalt’s blue was found to have imperfections in it’s wave. He also later discovered that other pigment-inducing elements possessed these faint imperfections as well, leading them come to believe they could prove if a color of light had come from an element by analyzing these differences—much like proving a diamond is real by seeing the carbon speckles through it. Another name would be “Cobalt crust”, named after the earthy arsenic of Cobalt which gives off a slightly lighter blue when ignited, and varying in color from they grayish tinge to a reddish-white. In addition, there also seems to have been a “Sevre’s blue”, resembling that of Thenard’s blue but no longer distinguished today.
© Mallory Woodard |