Ferrous metallurgy is the metallurgy of iron and its alloys. It began far back in prehistory; the earliest surviving iron artifacts, from the 4th millennium BC in Egypt, were made from meteoritic iron-nickel. It is not known when or where the smelting of iron from ores began, but by the end of the 2nd millennium BC iron was being produced from iron ores from Sub-Saharan Africa to China; the use of wrought iron was known by the 1st millennium BC, its spread marked the Iron Age. During the medieval period, means were found in Europe of producing wrought iron from cast iron using finery forges. For all these processes, charcoal was required as fuel. Steel was first produced in antiquity as an alloy, its process of production, Wootz steel, was exported before the 4th century BC from India to ancient China, the Middle East and Europe. Archaeological evidence of cast iron appears in 5th-century BC China. New methods of producing it by carburizing bars of iron in the cementation process were devised in the 17th century.
During the Industrial Revolution, new methods of producing bar iron by substituting coke for charcoal were devised and these were applied to produce steel, creating a new era of increased use of iron and steel that some contemporaries described as a new Iron Age. In the late 1850s, Henry Bessemer invented a new steelmaking process, that involved blowing air through molten pig iron to burn off carbon, so to produce mild steel; this and other 19th-century and steel making processes have displaced wrought iron. Today, wrought iron is no longer produced on a commercial scale, having been displaced by the functionally equivalent mild or low carbon steel; the largest and most modern underground iron ore mine in the world is located in Kiruna, Norrbotten County, Lapland. The mine, owned by Luossavaara-Kiirunavaara AB, a large Swedish mining company, has an annual production capacity of over 26 million tonnes of iron ore. Iron was extracted from iron–nickel alloys, which comprise about 6% of all meteorites that fall on the Earth.
That source can be identified with certainty because of the unique crystalline features of that material, which are preserved when the metal is worked cold or at low temperature. Those artifacts include, for example, a bead from the 5th millennium BC found in Iran and spear tips and ornaments from Ancient Egypt and Sumer around 4000 BC; these early uses appear to have been ceremonial or ornamental. Meteoritic iron is rare, the metal was very expensive more expensive than gold; the early Hittites are known to have bartered iron for silver, at a rate of 40 times the iron's weight, with the Old Assyrian Empire in the first centuries of the second millennium BC. Meteoric iron was fashioned into tools in the Arctic, about the year 1000, when the Thule people of Greenland began making harpoons, knives and other edged tools from pieces of the Cape York meteorite. Pea-size bits of metal were cold-hammered into disks and fitted to a bone handle; these artifacts were used as trade goods with other Arctic peoples: tools made from the Cape York meteorite have been found in archaeological sites more than 1,000 miles distant.
When the American polar explorer Robert Peary shipped the largest piece of the meteorite to the American Museum of Natural History in New York City in 1897, it still weighed over 33 tons. Another example of a late use of meteoritic iron is an adze from around 1000 AD found in Sweden. Native iron in the metallic state occurs as small inclusions in certain basalt rocks. Besides meteoritic iron, Thule people of Greenland have used native iron from the Disko region. Iron smelting—the extraction of usable metal from oxidized iron ores—is more difficult than tin and copper smelting. While these metals and their alloys can be cold-worked or melted in simple furnaces and cast into molds, smelted iron requires hot-working and can be melted only in specially designed furnaces. Iron is a common impurity in copper ores and iron ore was sometimes used as a flux, thus it is not surprising that humans mastered the technology of smelted iron only after several millennia of bronze metallurgy; the place and time for the discovery of iron smelting is not known because of the difficulty of distinguishing metal extracted from nickel-containing ores from hot-worked meteoritic iron.
The archaeological evidence seems to point to the Middle East area, during the Bronze Age in the 3rd millennium BC. However, wrought iron artifacts remained a rarity until the 12th century BC; the Iron Age is conventionally defined by the widespread replacement of bronze weapons and tools with those of iron and steel. That transition happened at different times as the technology spread. Mesopotamia was into the Iron Age by 900 BC. Although Egypt produced iron artifacts, bronze remained dominant until its conquest by Assyria in 663 BC; the Iron Age began in India about 1200 BC, in Central Europe about 600 BC, in China about 300 BC. Around 500 BC, the Nubians who had learned from the Assyrians the use of iron and were expelled from Egypt, became major manufacturers and exporters of iron. One of the earliest smelted iron artifacts, a dagger with an iron blade found in a Hattic tomb in Anatolia, dated from 2500 BC. About 1500 BC, increasing numbers of non-meteoritic, smelted iron objects appeared in Mesopotamia and Egypt.
Nineteen meteoric iron objects were found in the tomb of Egyptian ruler Tutankhamun, who died in 1323 BC, including an iron dagger with a golden hilt, an Eye of Horus, the mummy's head-stand and sixteen
Orichalcum or aurichalcum is a metal mentioned in several ancient writings, including the story of Atlantis in the Critias of Plato. Within the dialogue, Critias claims that orichalcum had been considered second only to gold in value and had been found and mined in many parts of Atlantis in ancient times, but that by Critias' own time orichalcum was known only by name. Orichalcum may have been a noble metal such as platinum, as it was supposed to be mined, or one type of bronze or brass or some other metal alloy. In 2015, metal ingots were found in an ancient shipwreck in Gela, which were made of an alloy consisting of copper and small percentages of nickel and iron. In numismatics, orichalcum is the golden-colored bronze alloy used by the Roman Empire for their sestertius and dupondius coins; the name is derived from the Greek ὀρείχαλκος, meaning "mountain copper". The Romans transliterated "orichalcum" as "aurichalcum", thought to mean "gold copper", it is known from the writings of Cicero that the metal which they called orichalcum resembled gold in color but had a much lower value.
In Virgil's Aeneid, the breastplate of Turnus is described as "stiff with gold and white orichalc". Orichalcum has been held to be either a gold-copper alloy, a copper-tin or copper-zinc brass, or a metal or metallic alloy no longer known. In years, "orichalcum" was used to describe the sulfide mineral chalcopyrite and to describe brass. However, these usages are difficult to reconcile with the claims of Plato's Critias, who states that the metal was "only a name" by his time, while brass and chalcopyrite were important in the time of Plato, as they still are today. Joseph Needham notes that 18th century Bishop Richard Watson, a professor of chemistry, wrote of an ancient idea that there were "two sorts of brass or orichalcum". Needham suggests that the Greeks may not have known how orichalcum was made, that they might have had an imitation of the original. In 2015, 39 ingots believed to be orichalcum were discovered in a sunken vessel on the coasts of Gela in Sicily which have tentatively been dated at 2,600 years old.
They were analyzed with X-ray fluorescence by Dario Panetta of Technologies for Quality and turned out to be an alloy consisting of 75-80 percent copper, 15-20 percent zinc, smaller percentages of nickel and iron. Orichalcum is first mentioned in the 7th century BC by Hesiod, in the Homeric hymn dedicated to Aphrodite, dated to the 630s. According to the Critias of Plato, the three outer walls of the Temple to Poseidon and Cleito on Atlantis were clad with brass and the third outer wall, which encompassed the whole citadel, "flashed with the red light of orichalcum"; the interior walls and floors of the temple were covered in orichalcum, the roof was variegated with gold and orichalcum. In the center of the temple stood a pillar of orichalcum, on which the laws of Poseidon and records of the first son princes of Poseidon were inscribed. Pliny the Elder points out. Pseudo-Aristotle in De mirabilibus auscultationibus describes a type of copper, "very shiny and white, not because there is tin mixed with it, but because some earth is combined and molten with it."
This might be a reference to orichalcum obtained during the smelting of copper with the addition of "cadmia", a kind of earth found on the shores of the Black Sea, attributed to be zinc oxide. In numismatics, the term "orichalcum" is used to refer to the golden-colored bronze alloy used for the sestertius and dupondius coins, it is considered more valuable than copper. Media related to Orichalcum coins at Wikimedia Commons
A fibula is a brooch or pin for fastening garments at the right shoulder. The fibula developed in a variety of shapes. Technically, the Latin term, refers to Roman brooches, its use in English is more restricted than in other languages, in particular post-Roman brooches from the British Isles are just called brooches, where in German they would be fibulae. Unlike most modern brooches, fibulae were not only decorative. Fibulae replaced straight pins that were used to fasten clothing in the Neolithic period and the Bronze Age. In turn, fibulae were replaced as clothing fasteners by buttons in the Middle Ages, their descendant, the modern safety pin, remains in use today. In ancient Rome and other places where Latin was used, the same word denoted both a brooch and the fibula bone because a popular form for brooches and the shape of the bone were thought to resemble one another; some fibulae were sometimes used as votive gifts for gods. There are hundreds of different types of fibulae, they are divided into families that are based upon historical periods, and/or cultures.
Fibulae are divided into classes that are based upon their general forms. Lost fibulae fragments, are dug up by amateur coin and relic hunters using metal detectors. Most fibulae are made of both; some fibulae are made of precious metals such as gold. Most fibulae are made of two pieces. Many fibulae are decorated with enamel, semi-precious stones, coral or bone. Fibulae were composed of four components: The body, pin and hinge; the body of a fibula is known depending on the basic form. A bow is long and narrow, arched. A plate is wide. Plates could openwork; the body was decorated. The head is the end of the fibula with the hinge; the foot is the end of the fibula. Depending on the type of fibula, the culture in question, the head of the fibula could be worn facing up, down or sideways; the pin, used to fasten the clothing is either a continuation of the fibula's body or a separate piece attached to the body. The fibula is closed by connecting the end of the pin to a catch pin rest; the body and pin hinge.
The earliest design is the spring. The spring could be bilateral. A unilateral spring winds around in one direction only. Unilateral springs are the earliest type, first appearing around the 14th century BC. Bilateral springs wind in one or more loops on one side of the pin and cross over or under the bow and continue with more loops on the other side, they appeared around the 6th century BC. Bilateral springs can be short, with only one or two revolutions per side, or up to 10 cm long. Most bilateral springs are made of one piece of metal and therefore have a spring cord, a piece of wire extending from one end of the spring to the other; the spring cord can pass in front behind the fibulae body. Bilateral springs wrap around a axle; these are made of iron if the rest of the fibula and spring is copper alloy. In the 1st century AD some fibulae had springs that were concealed under a metal cover, an extension of the fibula body; these are known as hidden springs. In the late 1st century BC or early 1st century AD a new design appeared in some bow type fibulae.
A separate pin was attached to the head-end of the bow with a small hinge. In the second half of the 1st century AD, hinges were introduced to plate type fibulae. One or two small plaques were cast on the back of the plate and a pin was attached to them by a small hinge. Plate type fibulae had bilateral springs attached to the back. In the 3rd century AD, the hinge was placed in the centre of a long transverse bar creating the famous crossbow fibula design. A few fibulae from a much earlier date had hinges, although this design feature was rare and soon died out for nearly five centuries. For example, the Asia Minor Decorated Arc Fibula dating to the 5th century BC, it is important to note. Though the introduction of the hinge was than the introduction of the spring, the spring remained in use long after the hinge was introduced. Therefore, a given fibula with hinge is not more recent than one with a spring. Fibulae were used to fasten clothing, they represent an improvement on the earlier straight pin, less secure and could fall out.
While the head of the earlier straight pin was decorated, the bow or plate of the fibula provided a much increased scope for decoration. Among some cultures, different fibula designs had specific symbolic meanings, they could refer to a status or profession such as single woman, married woman, warrior, or chief. Some Roman-era fibulae may symbolize specific positions in the Roman legions or auxiliary. In some cultures, fibulae could be linked by a length of chain; the Romans used fibulas to fasten the foreskin above the penis, thus hiding the glans, this was done both to show modesty and in the belief that it helped preserve the voice. The first fibulae design, violin bow fibulae, appeared in the late Bronze Age; this simpl
A micrometeorite is a micrometeoroid that has survived entry through Earth's atmosphere. The size of such a particle ranges from 50 µm to 2 mm. Found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, different in composition, they are a subset of cosmic dust, which includes the smaller interplanetary dust particles. Micrometeorites enter Earth's atmosphere at high velocities and undergo heating through atmospheric friction and compression. Micrometeorites individually weigh between 10−9 and 10−4 g and collectively comprise most of the extraterrestrial material that has come to the present-day Earth. Fred Lawrence Whipple first coined the term "micro-meteorite" to describe dust-sized objects that fall to the Earth. Sometimes meteoroids and micrometeoroids entering the Earth's atmosphere are visible as meteors or "shooting stars", whether or not they reach the ground and survive as meteorites and micrometorites. Micrometeorite textures vary as their original structural and mineral compositions are modified by the degree of heating that they experience entering the atmosphere—a function of their initial speed and angle of entry.
They range from unmelted particles that retain their original mineralogy, to melted particles to round melted cosmic spherules some of which have lost a large portion of their mass through vaporization. Classification is based on degree of heating; the extraterrestrial origins of micrometeorites are determined by microanalyses that show that: The metal they contain is similar to that found in meteorites. Some have wüstite, a high-temperature iron oxide found in meteorite fusion crusts, their silicate minerals have trace elements ratios similar to those in meteorites. The abundances of cosmogenic manganese in iron spherules and of cosmogenic beryllium and solar neon isotope in stony MMs are extraterrestrial The presence of pre-solar grains in some MMs and deuterium excesses in ultra-carbonaceous MMs indicates that they are not only extraterrestrial but that some of their components formed before our solar system. An estimated 30,000 ± 20,000 tonnes per year of cosmic dust enters the upper atmosphere each year of which less than 10% is estimated to reach the surface as particles.
Therefore, the mass of micrometeorites deposited is 50 times higher than that estimated for meteorites, which represent 50 t/yr, the huge number of particles entering the atmosphere each year suggests that large MM collections contain particles from all dust producing objects in the Solar System including asteroids and fragments from our Moon and Mars. Large MM collections provide information on the size, atmospheric heating effects and types of materials accreting on Earth while detailed studies of individual MMs give insights into their origin, the nature of the carbon, amino acids and pre-solar grains they contain. Micrometeorites have been collected from sedimentary rocks and polar sediments; because of their low concentrations on the Earth's surface, MMs are sought in environments that concentrate these materials relative to terrestrial particles. Melted micrometeorites were first collected from deep-sea sediments during the 1873 to 1876 expedition of HMS Challenger. In 1891, Murray and Renard found "two groups: first, black magnetic spherules, with or without a metallic nucleus.
In 1883, they suggested that these spherules were extraterrestrial because they were found far from terrestrial particle sources, they did not resemble magnetic spheres produced in furnaces of the time, their nickel-iron metal cores did not resemble metallic iron found in volcanic rocks. The spherules were most abundant in accumulating sediments red clays deposited below the carbonate compensation depth, a finding that supported a meteoritic origin. In addition to those spheres with Fe-Ni metal cores, some spherules larger than 300 µm contain a core of elements from the platinum group. Since the first collection of HMS Challenger, cosmic spherules have been recovered from ocean sediments using cores, box cores, clamshell grabbers, magnetic sleds. Among these a magnetic sled, called the "Cosmic Muck Rake", retrieved thousands of cosmic spherules from the top 10 cm of red clays on the Pacific Ocean floor. Terrestrial sediments contain micrometeorites; these have been found in samples that: Have low sedimentation rates such as claystones and hardgrounds Are dissolved such as salt deposits and limestones Have been mass sorted such as heavy mineral concentrates found in deserts and beach sands.
The oldest MMs are altered iron spherules found in 140- to 180-million-year-old hardgrounds. Amateur collectors may find micrometeorites in areas where dirt and dust from a large area has been concentrated, such as from a roof downspout. Micrometeorites found in polar sediments are much less weathered than those found in other terrestrial environments, as evidenced by little etching of interstitial glass, the presence of large numbers of glass spherules and unmelted micrometeorites, particle types that are rare or absent in deep-sea samples; the MMs found in polar regions have been collected from Greenland snow, Greenland cryoconite, Antarctic blue ice Antarctic aeolian debris, ice cores, the bottom of the South Pole water well, Antarctic sediment traps and present day Antarctic snow. Modern classification of mete
In archaeological terms, a projectile point is an object, hafted to weapon, capable of being thrown or projected, such as a spear, dart, or arrow, or used as a knife. They are thus different from weapons presumed to have been kept in the hand, such as axes and maces, the stone mace or axe-heads attached to them. Stone tools, including projectile points, can survive for long periods, were lost or discarded, are plentiful at archaeological sites, providing useful clues to the human past, including prehistoric trade. A distinctive form of point, identified though lithic analysis of the way it was made, is a key diagnostic factor in identifying an archaeological industry or culture. Scientific techniques exist to track the specific kinds of rock or minerals that used to make stone tools in various regions back to their original sources; as well as stone, projectile points were made of worked bone, antler or ivory. In regions where metallurgy emerged, projectile points were made from copper, bronze, or iron, though the change was by no means immediate.
In North America, some late prehistoric points were fashioned from copper, mined in the Lake Superior region and elsewhere. A large variety of prehistoric arrowheads, dart points, spear points have been discovered. Flint, obsidian and many other rocks and minerals were used to make points in North America; the oldest projectile points found in North America were long thought to date from about 13,000 years ago, during the Paleo-Indian period, however recent evidence suggests that North American projectile points may date to as old as 15,500 years. Some of the more famous Paleo-Indian types include Clovis and Dalton points. Projectile points fall into two general types: dart/spear points, arrow points. Larger points were used to atlatl darts. Arrow points are smaller and lighter than dart points, were used to tip arrows; the question of how to distinguish an arrow point from a point used on a larger projectile is non-trivial. According to some investigators, the best indication is the width of the hafting area, thought to correlate to the width of the shaft.
An alternative approach is to distinguish arrow points by their smaller size. Projectile points come in an amazing variety of shapes and styles, which vary according to chronological periods, cultural identities, intended functions. Typological studies of projectile points have become more elaborate through the years. For instance, Gregory Perino began his categorical study of projectile point typology in the late 1950s. Collaborating with Robert Bell, he published a set of four volumes defining the known point types of that time. Perino followed this several years with a three-volume study of "Selected Preforms and Knives of the North American Indians". Another recent set of typological studies of North American projectile points has been produced by Noel Justice. Bare Island projectile point Cascade point Clovis point Cumberland point Eden point Folsom point Greene projectile point Jack's Reef pentagonal projectile point Lamoka projectile point Levanna projectile point Susquehanna broad projectile point Plano point Elf-arrows Levallois technique Lithic reduction
Panchaloha called Panchadhatu or Panchdhatu is a term for traditional five-metal alloys of sacred significance, used for making Hindu temple murtis and jewelry. The composition is laid down in the Shilpa shastras, a collection of ancient texts that describe arts and their design rules and standards. Panchaloha is traditionally described as an alloy of gold, copper and iron as the major constituents. In some cases tin or lead is used instead of zinc, it is believed that wearing jewellery made of such an alloy brings balance in life, self-confidence, good health, fortune and peace of mind. In Tibetan culture, it was considered auspicious to use thokcha either as a component of the alloy in general or for a specific object or purpose; the amount used could vary, depending upon the material's availability and suitability, among other considerations. A small symbolic quantity of "sky-iron" might be added, or it might be included as a significant part of the alloy-recipe. Media related to Panchaloha at Wikimedia Commons Media related to Objects made from meteoritic iron at Wikimedia Commons The Lost-Wax Casting of Icons, Utensils and Other Items in South India, R.
M. Pillai, S. G. K. Pillai, A. D. Damodaran, October 2002, JOM