A murti is an image, statue or idol of a deity or person in Indian culture. In Hindu temples, it is a symbolic icon. A Murti is itself not the god in Hinduism, but it is a shape, embodyment or manifestation of a deity. Murtis are found in some nontheistic Jainism traditions, where they serve as symbols of revered persons inside Jain temples, are worshipped in Murtipujaka rituals. A Murti is made by carving stone, wood working, metal casting or through pottery. Ancient era texts describing their proper proportions and gestures include the Puranas and Samhitas; the expressions in a Murti vary in diverse Hindu traditions, ranging from Ugra symbolism to express destruction and violence, as well as Saumya symbolism to express joy and harmony. Saumya images are most common in Hindu temples. Other Murti forms found in Hinduism include the Linga. A Murti is an embodiment of the Ultimate Reality or Brahman to some Hindus. In religious context, they are found in Hindu temples or homes, where they may be treated as a beloved guest and serve as a participant of Puja rituals in Hinduism.
In other occasions, it serves as the center of attention in annual festive processions and these are called Utsava Murti. The earliest murtis are mentioned by Pāṇini in 4th century BCE. Prior to that the agnicayana ritual ground seemed to served as a template for the temple. Murti is sometimes referred to vigraha or pratima. Murti means any solid body or form with definite shape or limits produced from material elements, it contrasts with mind and the immaterial in ancient Indian literature. The term refers to any embodiment, incarnation, appearance, idol or statue of a deity; the earliest mention of the term Murti occurs in primary Upanishads composed in the 1st millennium BCE in verse 3.2 of Aitareya Upanishad, verse 1.13 of Shvetashvatara Upanishad, verse 6.14 of Maitrayaniya Upanishad and verse 1.5 of Prashna Upanishad. For example, the Maitrayaniya Upanishad uses the term to mean a "form, manifestation of time"; the section sets out to prove Time exists, acknowledges the difficulty in proving Time exists by Pramana inserts a theory of inductive inference for epistemological proof as follows, The section includes the concept of Time and non-Time, stating that non-Time as that which existed before creation of universe, time as which came into existence with the creation of universe.
Non-Time is indivisible, Time is divisible, the Maitri Upanishad asserts that "Year is the Murti of time". Robert Hume translates the discussion of Murti of time, in verse 6.14 of the Maitri Upanishad, as "form". Most scholars, such as Jan Gonda, Max Muller, PV Kane and Stephanie Jamison, state that there were neither Murti nor temples nor idol-facilitated worship in the Vedic era; the Vedic Hinduism rituals were directed at nature and abstract deities called during yajna with hymns. However, there isn't universal consensus, with scholars such as AC Das, pointing to the word Mūradeva in Rig Veda verses 7.104.24, 10.87.2 and 10.87.14. This word may refer to "Deva, fixed" or "Deva, foolish"; the former interpretation, if accurate, may imply that there were communities in the Vedic era who had Devas in the form of Murti, the context of these hymns suggest that the term could be referring to practices of the tribal communities outside of the Vedic fold. One of the earliest firm textual evidence of Deva images, in the sense of Murti, is found in Jivikarthe Capanye by the Sanskrit grammarian Pāṇini who lived about 4th century BCE.
He mentions Acala and Cala, with former referring to images in a shrine, the latter meaning images that were carried from place to place. Panini mentions Devalaka, meaning custodians of images of worship who show the images but do not sell them, as well as Jivika as people whose source of livelihood was the gifts they received from devotees. In ancient Sanskrit texts that follow Panini's work, numerous references are found to divine images with terms such as Devagrha, Devakula and others; these texts, states Noel Salmond suggest that temples and Murti were in existence in ancient India by about 4th century BCE. Recent archaeological evidence confirms that the knowledge and art of sculpture was established in India by the Maurya Empire period. By early 1st millennium BCE, the term Murti meant idols, image or statue in various Indian texts such as Bhavishya Purana verse 132.5.7, Brihat Samhita 1.8.29 and inscriptions in different parts of India. The term Murti has been a more generic term referring to an idol or statue of anyone, either a deity, of any human being, animal or any art.
Pratima includes Murti as well as painting of any non-anthropomorphic object. In contrast, Bera or Bimba meant "idol of god" only, Vigraha was synonymous with Bimba. A Murti in contemporary usage is any statue, it may be found inside or outside a temple or home, installed to be moved with a festive procession, or just be a landmark. It is a significant part of Hindu iconography, is implemented in many ways. Two major categories include: Ugra - are images that were meant to terrify, induce fear; these have wide, circular eyes, carry weapons, have skulls and bones as adornment. These idols were worshipped by soldiers before going to war, or by people in times of distress or errors. Raudra deity temples were not set up inside villages or towns, but invariably outside and in remote areas of a kingdom. Shanta and Saumya - are images that were pacific and expressive of love, compassi
Iron meteorites are meteorites that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that consists of two mineral phases: kamacite and taenite. Iron meteorites originate from cores of planetesimals; the iron found in iron meteorites was one of the earliest sources of usable iron available to humans, before the development of smelting that signaled the beginning of the Iron Age. Although they are rare compared to the stony meteorites, comprising only about 5.7% of witnessed falls, iron meteorites have been over-represented in meteorite collections. This is due to several factors: They are recognized as unusual by laymen, as opposed to stony meteorites. Modern-day searches for meteorites in deserts and Antarctica yield a much more representative sample of meteorites overall, they are much more resistant to weathering. They are much more to survive atmospheric entry, are more resistant to the resulting ablation. Hence, they are more to be found as large pieces, they can be found when buried by use of surface metal detecting equipment, due to their metallic composition.
Because they are denser than stony meteorites, iron meteorites account for 90% of the mass of all known meteorites, about 500 tons. All the largest known meteorites are of this type, including the largest—the Hoba meteorite. Iron meteorites have been linked to M-type asteroids because both have similar spectral characteristics in the visible and near-infrared. Iron meteorites are thought to be the fragments of the cores of larger ancient asteroids that have been shattered by impacts; the heat released from the radioactive decay of the short-lived nuclides 26Al and 60Fe is considered as a plausible cause for the melting and differentiation of their parent bodies in the early Solar System. Melting produced from the heat of impacts is another cause of melting and differentiation The IIE iron meteorites may be a notable exception, in that they originate from the crust of S-type asteroid 6 Hebe. Chemical and isotope analysis indicates; this implies that there were once at least this many large, asteroids in the asteroid belt – many more than today.
The overwhelming bulk of these meteorites consists of the FeNi-alloys taenite. Minor minerals, when occurring form rounded nodules of troilite or graphite, surrounded by schreibersite and cohenite. Schreibersite and troilite occur as plate shaped inclusions, which show up on cut surfaces as cm-long and mm-thick lamellae; the troilite plates are called Reichenbach lamellae. The chemical composition is dominated by the elements Fe, Ni and Co, which make up more than 95%. Ni is always present. A significant percentage of nickel can be used in the field to distinguish meteoritic irons from man-made iron products, which contain lower amounts of Ni, but it is not enough to prove meteoritic origin. Iron meteorites were used for their meteoric iron, forged into cultural objects, tools or weapons. With the advent of smelting and the beginning of the iron age the importance of iron meteorites as a resource decreased, at least in those cultures that developed those techniques; the Inuit used the Cape York meteorite for a much longer time.
Iron meteorites themselves were sometimes used unaltered as collectibles or religious symbols. Today iron meteorites are prized collectibles for academic individuals; some are tourist attractions as in the case of the Hoba meteorite. Two classifications are in use: the classic structural classification and the newer chemical classification; the older structural classification is based on the presence or absence of the Widmanstätten pattern, which can be assessed from the appearance of polished cross-sections that have been etched with acid. This is connected with the relative abundance of nickel to iron; the categories are: Hexahedrites: no Widmanstätten pattern, may present Neumann lines. They can be further divided up on the basis of the width of the kamacite lamellae from coarsest to finest. Coarsest: lamellae width > 3.3 mm Coarse: lamellae width 1.3-3.3 mm Medium: lamellae width 0.5-1.3 mm Fine: lamellae width 0.2-0.5 mm Finest: lamellae width < 0.2 mm Plessitic: a transitional structure between octahedrites and ataxites Ataxites: high nickel, no Widmanstätten pattern, rare.
A newer chemical classification scheme based on the proportions of the trace elements Ga, Ge and Ir separates the iron meteorites into classes corresponding to distinct asteroid parent bodies. This classification is based on diagrams; the different iron meteorite groups appear as data point clusters. There were four of these groups designated by the Roman numerals I, II, III, IV; when more chemical data became available these were split, e.g. Group IV was split into IVA and IVB meteorites; some groups got joined again when intermediate meteorites were discovered, e.g. IIIA and IIIB were combined into the IIIAB meteorites. In 2006 iron meteorites were classified into 13 groups: IAB IA: Medium and coarse octahedrites, 6.4-8.7% Ni, 55-100 ppm Ga, 190-520 ppm Ge, 0.6-5.5 ppm Ir, Ge-Ni correlation negative. IB: Ataxites and medium octahedrites, 8.7-25% Ni, 11-55 ppm Ga, 25-190 ppm Ge, 0.3-2 ppm Ir, Ge-Ni correlation negative. IC IIAB IIA: Hexahedrites, 5.3-5.7% Ni, 57-62 ppm Ga, 170-185 ppm Ge, 2-60ppm Ir.
IIB: Coarsest oct
Shakudō is a Japanese billon of gold and copper, one of the irogane class of colored metals, which can be treated to develop a black, or sometimes indigo, resembling lacquer. Unpatinated shakudō visually resembles bronze; the characters in the name shaku-dō mean "red" and "copper" but combined they represent this material which begins with a darkened coppery-bronze color and is modified to black or near-black. The word "shakudō" first appears in records of the Japanese "Nara" period, but it is not clear to what it referred. There are actual pieces known from the 12th century onwards. Shakudō was used to construct or decorate Japanese sword fittings such as tsuba and kozuka, as well as other small ornaments, sliding door catches, small boxes. Shakudō was introduced to the West in the mid-19th century. Materials like shakudo were thought to be specific to the Chinese and Japanese, other Asian, but recent studies have noted close similarities to certain decorative alloys used in ancient Egypt and Rome.
The origins of shakudo date back to a period when Japan was still importing significant techniques and materials from Korea and China, but accounts of production all derive from much and little is known of their evolution. By the Meiji period, the initial production process entailed the heating of copper, addition of fine gold, some addition of shirome, a by-product of copper production containing iron and other elements. In the Edo period, it appears; the resulting alloy was allowed to rest in ingot moulds in heated water, before being shaped, annealed at around 650° C. In cooled form, the metal was surface-finished using the niiro process; the modern process tends to omit the shirome, working with copper and gold, other additives directly if needed. Due to the expensive gold content, shakudō was limited to accents or small items such as tsuba. Larger historical objects that are described as shakudō may be mislabeled if the glossy blue-black color is not evident. Unpatinated or repolished shakudō will not spontaneously patinate in air.
Modern artisans have revived the use of shakudō as a striking design element, in the making of jewelry and for the technique of mokume-gane. Shakudō is sometimes inaccurately used as a general term for damascened decorative metal inlays of Japanese origin; these were known in the West as Amita damascene, from the name of a 20th-century manufacturer of such items for export. Amita damascene included shakudo, gold and bronze for inlays. Oguchi, Hachiro. Japanese Shakudo: Its History and Production from Gold-Containing Alloys. Gold Bulletin, 16, 4, 1983, pp. 125–132 doi:10.1007/BF03214636 National Pollutant Inventory – Copper and compounds fact sheet History of the Amita Damascene Company
Hinduism is an Indian religion and dharma, or way of life practised in the Indian subcontinent and parts of Southeast Asia. Hinduism has been called the oldest religion in the world, some practitioners and scholars refer to it as Sanātana Dharma, "the eternal tradition", or the "eternal way", beyond human history. Scholars regard Hinduism as a fusion or synthesis of various Indian cultures and traditions, with diverse roots and no founder; this "Hindu synthesis" started to develop between 500 BCE and 300 CE, after the end of the Vedic period, flourished in the medieval period, with the decline of Buddhism in India. Although Hinduism contains a broad range of philosophies, it is linked by shared concepts, recognisable rituals, shared textual resources, pilgrimage to sacred sites. Hindu texts are classified into Smṛti; these texts discuss theology, mythology, Vedic yajna, agamic rituals, temple building, among other topics. Major scriptures include the Vedas and Upanishads, the Bhagavad Gita, the Ramayana, the Āgamas.
Sources of authority and eternal truths in its texts play an important role, but there is a strong Hindu tradition of questioning authority in order to deepen the understanding of these truths and to further develop the tradition. Prominent themes in Hindu beliefs include the four Puruṣārthas, the proper goals or aims of human life, namely Dharma, Artha and Moksha. Hindu practices include rituals such as puja and recitations, meditation, family-oriented rites of passage, annual festivals, occasional pilgrimages; some Hindus leave their social world and material possessions engage in lifelong Sannyasa to achieve Moksha. Hinduism prescribes the eternal duties, such as honesty, refraining from injuring living beings, forbearance, self-restraint, compassion, among others; the four largest denominations of Hinduism are the Vaishnavism, Shaivism and Smartism. Hinduism is the world's third largest religion. Hinduism is the most professed faith in India and Mauritius, it is the predominant religion in Bali, Indonesia.
Significant numbers of Hindu communities are found in the Caribbean, North America, other countries. The word Hindū is derived from Indo-Aryan/Sanskrit root Sindhu; the Proto-Iranian sound change *s > h occurred between 850–600 BCE, according to Asko Parpola. It is believed that Hindu was used as the name for the Indus River in the northwestern part of the Indian subcontinent. According to Gavin Flood, "The actual term Hindu first occurs as a Persian geographical term for the people who lived beyond the river Indus", more in the 6th-century BCE inscription of Darius I; the term Hindu in these ancient records did not refer to a religion. Among the earliest known records of'Hindu' with connotations of religion may be in the 7th-century CE Chinese text Record of the Western Regions by Xuanzang, 14th-century Persian text Futuhu's-salatin by'Abd al-Malik Isami. Thapar states that the word Hindu is found as heptahindu in Avesta – equivalent to Rigvedic sapta sindhu, while hndstn is found in a Sasanian inscription from the 3rd century CE, both of which refer to parts of northwestern South Asia.
The Arabic term al-Hind referred to the people. This Arabic term was itself taken from the pre-Islamic Persian term Hindū, which refers to all Indians. By the 13th century, Hindustan emerged as a popular alternative name of India, meaning the "land of Hindus"; the term Hindu was used in some Sanskrit texts such as the Rajataranginis of Kashmir and some 16th- to 18th-century Bengali Gaudiya Vaishnava texts including Chaitanya Charitamrita and Chaitanya Bhagavata. These texts used it to distinguish Hindus from Muslims who are called Yavanas or Mlecchas, with the 16th-century Chaitanya Charitamrita text and the 17th-century Bhakta Mala text using the phrase "Hindu dharma", it was only towards the end of the 18th century that European merchants and colonists began to refer to the followers of Indian religions collectively as Hindus. The term Hinduism spelled Hindooism, was introduced into the English language in the 18th century to denote the religious and cultural traditions native to India. Hinduism includes a diversity of ideas on spirituality and traditions, but has no ecclesiastical order, no unquestionable religious authorities, no governing body, no prophet nor any binding holy book.
Because of the wide range of traditions and ideas covered by the term Hinduism, arriving at a comprehensive definition is difficult. The religion "defies our desire to define and categorize it". Hinduism has been variously defined as a religion, a religious tradition, a set of religious beliefs, "a way of life". From a Western lexical standpoint, Hinduism like other faiths is appropriately referred to as a religion. In India the term dharma is preferred, broader than the Western term religion; the study of India and its cultures and religions, the definition of "Hinduism", has been shaped by th
Tumbaga is the name for a non-specific alloy of gold and copper given by Spanish Conquistadors to metals composed of these elements found in widespread use in pre-Columbian Mesoamerica and South America. The term is believed to be a borrowing from Malay tembaga, meaning "copper" or "brass", which in turn is from Prakrit. Tumbaga is an alloy composed of gold and copper, it has a lower melting point than gold or copper alone. It maintains malleability after being pounded. Tumbaga can be treated like citric acid, to dissolve copper off the surface. What remains is a shiny layer of nearly pure gold on top of a harder, more durable copper-gold alloy sheet; this process is referred to as depletion gilding. Tumbaga was used by the pre-Columban cultures of Central America to make religious objects. Like most gold alloys, tumbaga was versatile and could be cast, hammered, soldered, plated, annealed, engraved and inlaid; the proportion of gold to copper in artifacts varies widely. Some tumbaga has been found to be composed of metals besides gold and copper, up to 18% of the total mass of the tumbaga.
Tumbaga objects were made using a combination of the lost wax technique and depletion gilding. An alloy of varying proportions of copper and gold was cast. After removal it was burned, turning surface copper into copper oxide, mechanically removed The object was placed in an oxidizing solution composed of sodium chloride and ferric sulfate; this dissolved the silver from the surface. When viewed through a microscope, voids appear where the silver had been. In 1992 200 silver "tumbaga" bars were recovered in wreckage off Grand Bahama Island, they were composed of silver and gold plundered by the Spaniards during the conquests of Cortés and hastily melted into bars of tumbaga for transport across the Atlantic. Such bars were melted back into their constituent metals in Spain. Shipwreck recovered right after the conquest of Cortés with tumbaga gold bars The "Tumbaga" Saga: Treasure of the Conquistadors. Book about Tumbaga Bars The Art of Precolumbian Gold: The Jan Mitchell Collection, an exhibition catalog from The Metropolitan Museum of Art, which contains material on Tumbaga
Bronze is an alloy consisting of copper with about 12–12.5% tin and with the addition of other metals and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as stiffness, ductility, or machinability; the archeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in India and western Eurasia is conventionally dated to the mid-4th millennium BC, to the early 2nd millennium BC in China; the Bronze Age was followed by the Iron Age starting from about 1300 BC and reaching most of Eurasia by about 500 BC, although bronze continued to be much more used than it is in modern times. Because historical pieces were made of brasses and bronzes with different compositions, modern museum and scholarly descriptions of older objects use the more inclusive term "copper alloy" instead. There are two basic theories as to the origin of the word.
Romance theoryThe Romance theory holds that the word bronze was borrowed from French bronze, itself borrowed from Italian bronzo "bell metal, brass" from either, bróntion, back-formation from Byzantine Greek brontēsíon from Brentḗsion ‘Brindisi’, reputed for its bronze. Proto-Slavic theoryThe Proto-Slavic theory reflects the philological issue that in the most of Slavonic languages word "bronza" corresponds to "war metal" while at the early stages of the Bronze working it was used exclusively for military purposes; the discovery of bronze enabled people to create metal objects which were harder and more durable than possible. Bronze tools, weapons and building materials such as decorative tiles were harder and more durable than their stone and copper predecessors. Bronze was made out of copper and arsenic, forming arsenic bronze, or from or artificially mixed ores of copper and arsenic, with the earliest artifacts so far known coming from the Iranian plateau in the 5th millennium BC, it was only that tin was used, becoming the major non-copper ingredient of bronze in the late 3rd millennium BC.
Tin bronze was superior to arsenic bronze in that the alloying process could be more controlled, the resulting alloy was stronger and easier to cast. Unlike arsenic, metallic tin and fumes from tin refining are not toxic; the earliest tin-alloy bronze dates to 4500 BC in a Vinča culture site in Pločnik. Other early examples date to the late 4th millennium BC in Egypt and some ancient sites in China and Mesopotamia. Ores of copper and the far rarer tin are not found together, so serious bronze work has always involved trade. Tin sources and trade in ancient times had a major influence on the development of cultures. In Europe, a major source of tin was the British deposits of ore in Cornwall, which were traded as far as Phoenicia in the eastern Mediterranean. In many parts of the world, large hoards of bronze artifacts are found, suggesting that bronze represented a store of value and an indicator of social status. In Europe, large hoards of bronze tools socketed axes, are found, which show no signs of wear.
With Chinese ritual bronzes, which are documented in the inscriptions they carry and from other sources, the case is clear. These were made in enormous quantities for elite burials, used by the living for ritual offerings. Though bronze is harder than wrought iron, with Vickers hardness of 60–258 vs. 30–80, the Bronze Age gave way to the Iron Age after a serious disruption of the tin trade: the population migrations of around 1200–1100 BC reduced the shipping of tin around the Mediterranean and from Britain, limiting supplies and raising prices. As the art of working in iron improved, iron improved in quality; as cultures advanced from hand-wrought iron to machine-forged iron, blacksmiths learned how to make steel. Steel holds a sharper edge longer. Bronze was still used during the Iron Age, has continued in use for many purposes to the modern day. There are many different bronze alloys, but modern bronze is 88% copper and 12% tin. Alpha bronze consists of the alpha solid solution of tin in copper.
Alpha bronze alloys of 4–5% tin are used to make coins, springs and blades. Historical "bronzes" are variable in composition, as most metalworkers used whatever scrap was on hand; the proportions of this mixture suggests. The Benin Bronzes are in fact brass, the Romanesque Baptismal font at St Bartholomew's Church, Liège is described as both bronze and brass. In the Bronze Age, two forms of bronze were used: "classic bronze", about 10% tin, was used in
An alloy is a combination of metals and of a metal or another element. Alloys are defined by a metallic bonding character. An alloy may be a mixture of metallic phases. Intermetallic compounds are alloys with a defined crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a wide variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties. In other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, brass, duralumin and amalgams; the alloy constituents are measured by mass percentage for practical applications, in atomic fraction for basic science studies. Alloys are classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the alloy, they can be heterogeneous or intermetallic. An alloy is a mixture of chemical elements, which forms an impure substance that retains the characteristics of a metal.
An alloy is distinct from an impure metal in that, with an alloy, the added elements are well controlled to produce desirable properties, while impure metals such as wrought iron are less controlled, but are considered useful. Alloys are made by mixing two or more elements, at least one of, a metal; this is called the primary metal or the base metal, the name of this metal may be the name of the alloy. The other constituents may or may not be metals but, when mixed with the molten base, they will be soluble and dissolve into the mixture; the mechanical properties of alloys will be quite different from those of its individual constituents. A metal, very soft, such as aluminium, can be altered by alloying it with another soft metal, such as copper. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of non-metallic carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its very-high strength, but still substantial toughness, its ability to be altered by heat treatment, steel is one of the most useful and common alloys in modern use.
By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel. Like oil and water, a molten metal may not always mix with another element. For example, pure iron is completely insoluble with copper; when the constituents are soluble, each will have a saturation point, beyond which no more of the constituent can be added. Iron, for example, can hold a maximum of 6.67% carbon. Although the elements of an alloy must be soluble in the liquid state, they may not always be soluble in the solid state. If the metals remain soluble when solid, the alloy forms a solid solution, becoming a homogeneous structure consisting of identical crystals, called a phase. If as the mixture cools the constituents become insoluble, they may separate to form two or more different types of crystals, creating a heterogeneous microstructure of different phases, some with more of one constituent than the other phase has.
However, in other alloys, the insoluble elements may not separate until after crystallization occurs. If cooled quickly, they first crystallize as a homogeneous phase, but they are supersaturated with the secondary constituents; as time passes, the atoms of these supersaturated alloys can separate from the crystal lattice, becoming more stable, form a second phase that serve to reinforce the crystals internally. Some alloys, such as electrum, an alloy consisting of silver and gold, occur naturally. Meteorites are sometimes made of occurring alloys of iron and nickel, but are not native to the Earth. One of the first alloys made by humans was bronze, a mixture of the metals tin and copper. Bronze was an useful alloy to the ancients, because it is much stronger and harder than either of its components. Steel was another common alloy. However, in ancient times, it could only be created as an accidental byproduct from the heating of iron ore in fires during the manufacture of iron. Other ancient alloys include pewter and pig iron.
In the modern age, steel can be created in many forms. Carbon steel can be made by varying only the carbon content, producing soft alloys like mild steel or hard alloys like spring steel. Alloy steels can be made by adding other elements, such as chromium, vanadium or nickel, resulting in alloys such as high-speed steel or tool steel. Small amounts of manganese are alloyed with most modern steels because of its ability to remove unwanted impurities, like phosphorus and oxygen, which can have detrimental effects on the alloy. However, most alloys were not created until the 1900s, such as various aluminium, titanium and magnesium alloys; some modern superalloys, such as incoloy and hastelloy, may consist of a multitude of different elements. As a noun, the term alloy is used to describe a mixture of atoms in which the primary constituent is a metal; when used as a verb, the term refers to the act of mixing a metal with other elements. The primary metal is called the matrix, or the solvent; the secondary constituents are called s