Native metal

A native metal is any metal that is found pure in its metallic form in nature.[1][2] Metals that can be found as native deposits singly or in alloys include aluminium, antimony, arsenic, bismuth, cadmium, chromium, cobalt, indium, iron, manganese, molybdenum, nickel, niobium, rhenium, selenium, tantalum, tellurium, tin, titanium, tungsten, vanadium, and zinc, as well as two groups of metals: the gold group, and the platinum group. The gold group consists of gold, copper, lead, aluminium, mercury, and silver. The platinum group consists of platinum, iridium, osmium, palladium, rhodium, and ruthenium. Amongst the alloys found in native state have been brass, bronze, pewter, German silver, osmiridium, electrum, white gold, and silver-mercury and gold-mercury amalgam.

Only gold, silver, copper and the platinum metals occur in nature in large amounts. Over geological time scales, very few metals can resist natural weathering processes like oxidation, which is why generally only the less reactive metals such as gold and platinum are found as native metals. The others usually occur as isolated pockets where a natural chemical process reduces a common compound or ore of the metal, leaving the pure metal behind as small flakes or inclusions.

Non-metallic elements occurring in the native state include carbon and sulfur. Silicon, a semi-metal, has been found in the native state on rare occasions as small inclusions in gold.[3]

Native metals were prehistoric man's only access to metal, since the process of extracting metals from their ores, smelting, is thought to have been discovered around 6500 BC. However, they could be found only in relatively small amounts, so they could not be used extensively. So while copper and iron were known well before the copper age and Iron Age, they would not have a large impact on humankind until the technology to smelt them from their ores, and thus mass-produce them appeared.

Naturkundemuseum Berlin - Gediegen Gold in Quarz, Eagles Nest Mine, Placer County, Kalifornien, USA
Native gold partially embedded in quartz gangue
Platinum-nugget
Kondyor Mine Region Chabarowsk: native platinum nugget

Occurrence

Gold

Gold is the most well known of the native metals. Most gold is mined as native metal and can be found as nuggets, veins or wires of gold in a rock matrix, or fine grains of gold, mixed in with sediments or bound within rock. The iconic image of gold mining for many is gold panning, which is a method of separating flakes of pure gold from river sediments due to their great density. Native gold is the predominant gold mineral on the earth. It is sometimes found alloyed with silver and/or other metals but true gold compound minerals are uncommon, mainly a handful of selenides and tellurides.

Silver

Silber mineral erz
Silver with quartz matrix (5 x 3 cm)

Native silver occurs as elongated dendritic coatings or irregular masses. It may also occur as cubic, octahedral, or dodecahedral crystals. It may occur alloyed with gold as electrum. It often occurs with silver sulfide and sulfosalt minerals.[4][5] Various amalgams of silver and mercury or other metals and mercury do occur rarely as minerals in nature. An example is the mineral eugenite (Ag11Hg2) and related forms.[6] Silver nuggets, wires, and grains are relatively common, but there are also a large number of silver compound minerals owing to silver being more reactive than gold.

Platinum group

Natural alloys of the platinum group metals include: native osmium (Os,Ir,Ru), rutheniridosmine (Ir,Os,Ru), ruthenium (Ru,Ir), palladium (Pd,Pt), platinum Pt, and rhodium (Rh,Pt). In addition gold, copper, iron, mercury, tin and lead may occur in alloys of this group.[7] As with gold, salts and other compounds of the platinum group metals are rare; native platinum and related metals and alloys are the predominant minerals bearing these metals. These metals occur associated with ultramafic intrusions and placer deposits derived from those intrusions.

Copper

Native Copper from Michigan
Native Copper Specimen isolated from mineral matrix. From Keweenaw Peninsula, MI. Iroquois Copper Mine.

Native copper has been historically mined as an early source of the metal. The term Old Copper Complex is used to describe an ancient North American civilization that utilized native copper deposits for weapons, tools, and decorative objects. This society existed around Lake Superior, where they found sources of native copper and mined them between 6000 and 3000 BC.[8] Copper would have been especially useful to ancient man as it was much stronger than gold, hard enough to be made into useful items such as fishhooks and woodworking tools, but still soft enough to be easily shaped, unlike meteoric iron.

The same deposits of native copper on the Keweenaw Peninsula and Isle Royale were later mined commercially. From 1845 until 1887, the Michigan Copper Country was the leading producer of copper in the United States. Masses of native copper weighing hundreds of tons were sometimes found in the mines.

The spectrum of copper minerals closely resembles that of silver, ranging from oxides of its multiple oxidation states through sulfides and silicates to halides and chlorates, iodates, nitrates and others. Natural alloys of copper (particularly with silver; the two metals can also be found in separate but co-mingled masses) are also found.

Iron, nickel and cobalt

Most of the native iron on earth is actually not in fact "native", in the traditional sense, to Earth. It mainly comes from iron-nickel meteorites that formed millions of years ago but were preserved from chemical attack by the vacuum of space, and fell to the earth a relatively short time ago. Metallic meteorites are composed primarily of the iron-nickel alloys: taenite (high nickel content) and kamacite (low nickel content). However, there are a few areas on earth where truly native iron can be found.[9][10]

Native nickel has been described as serpentinite due to hydrothermal alteration of ultramafic rocks in New Caledonia and elsewhere.[11][12]

Metallic cobalt has been reported in the Canadian Lorraine Mine, Cobalt-Gowganda region, the Timiskaming District, Ontario, Canada, and in the Aidyrlya gold deposit in Orenburgskaya Oblast of the Southern Urals.[13]

Others

All other native metals occur only in small quantities or are found in geologically special regions. For example, metallic cadmium was only found at two locations including the Vilyuy River basin in Siberia.[14] Native molybdenum has been found in lunar regolith and in the Koryakskii volcano in Kamchatka Oblast of Russia.[15] Elsewhere in this region native indium, aluminium, tantalum, selenium, tellurium, and other metals have been reported. Native lead[16] is quite rare but somewhat more widespread, as are tin,[17] mercury,[18] arsenic,[19] antimony,[20] and bismuth.[21]

Native chromium has been found in small grains in Sichuan, China[22] and other locations.[23]

See also

References

  1. ^ "native metal". Oxford English Dictionary. Oxford University Press. Retrieved 30 January 2018.
  2. ^ Parker Cleaveland (1822). An elementary treatise on mineralogy and geology. Cummings and Hilliard. p. 521.
  3. ^ Silicon, Mindat.org
  4. ^ Handbook of Mineralogy
  5. ^ Webmineral data
  6. ^ Eugenite on Mindat (see related minerals and localities)
  7. ^ Iridium on Mindat, Relationship of Iridium to other Species - Nichel-Strunz
  8. ^ Thomas C. Pleger (2000). "The Old Copper Complex of the Western Great Lakes". UW–Fox Valley Anthropology. Archived from the original on 2008-07-05. Retrieved 2007-08-15.
  9. ^ Mindat with location data
  10. ^ Native iron in the Handbook of Mineralogy
  11. ^ Nickel on Mindat with location data
  12. ^ Native nickel in the Handbook of Mineralogy
  13. ^ Cobalt on Mindat
  14. ^ Fleischer, Michael; Cabri, Louis J.; Chao, George Y.; Pabst, Adolf (1980). "New Mineral Names" (PDF). American Mineralogist. 65: 1065–1070.
  15. ^ Native Molybdenum - Mindat.org
  16. ^ Lead on Mindat
  17. ^ Tin on Mindat
  18. ^ Mercury on Mindat
  19. ^ Arsenic on Mindat
  20. ^ Antimony on Mindat
  21. ^ Bismuth on Mindat
  22. ^ "Chromium Mineral Data". Webmineral.com. Retrieved 2013-05-09.
  23. ^ Chromium on Mindat

External links

Antimony

Antimony is a chemical element with the symbol Sb (from Latin: stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name, kohl. Metallic antimony was also known, but it was erroneously identified as lead upon its discovery. The earliest known description of the metal in the West was written in 1540 by Vannoccio Biringuccio.

For some time, China has been the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony are roasting and reduction with carbon or direct reduction of stibnite with iron.

The largest applications for metallic antimony are an alloy with lead and tin and the lead antimony plates in lead–acid batteries. Alloys of lead and tin with antimony have improved properties for solders, bullets, and plain bearings. Antimony compounds are prominent additives for chlorine and bromine-containing fire retardants found in many commercial and domestic products. An emerging application is the use of antimony in microelectronics.

Arandu Arakuaa

Arandu Arakuaa is a Brazilian folk metal band formed in the country's capital, Brasília. It is noted for blending extreme heavy metal with Brazilian folk music, specifically indigenous tunes. Their lyrics also reflect indigenous cultures, referring to their myths and rites. With bands Aclla, Armahda, Cangaço, Hate Embrace, MorrigaM, Tamuya Thrash Tribe and Voodoopriest, they form the Levante do Metal Nativo (Native Metal Uprising), a movement gathering bands that mix heavy metal with typical musical elements from that country and/or write lyrics about it.Guitarist and founder Zhândio Aquino claims to have been born and raised until the age of 24 near a Xerente territory, in the state of Tocantins, where he came in contact with indigenous music and Brazilian regional music namely (baião, catira, cantiga de roda, vaquejada, etc.). He cites Metallica and Black Sabbath as his influences from the metal side.

Armahda

Armahda is a Brazilian heavy metal band formed em 2011. They are known for dealing with themes related to the History of Brazil in their lyrics. With bands Aclla, Arandu Arakuaa, Cangaço, Hate Embrace, MorrigaM, Tamuya Thrash Tribe and Voodoopriest, they form the Levante do Metal Nativo (Native Metal Uprising), a movement gathering bands that mix heavy metal with typical musical elements from that country and/or write lyrics about it. The group cites Blind Guardian, Sabaton, Black Sabbath, classical 1970s bands and German power metal bands as influences.

Ataxite

Ataxites (from Greek meaning "without structure") are a structural class of iron meteorites with a high nickel content and show no Widmanstätten patterns upon etching.

Clearlight (American band)

Clearlight is an instrumental stoner rock band from New Orleans, Louisiana. They are also known as The Mystick Krewe of Clearlight due to other bands using the same original name.

Cobalt

Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought by alchemists [citation needed] to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue-pigment producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.

Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is however more usually produced as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. The DRC alone accounted for more than 50% of world production in 2016 (123,000 tonnes), according to Natural Resources Canada.Cobalt is primarily used in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high energy gamma rays.

Cobalt is the active center of a group of coenzymes called cobalamins. vitamin B12, the best-known example of the type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, and fungi.

Coloradoite

Coloradoite, also known as mercury telluride (HgTe), is a rare telluride ore associated with metallic deposit (especially gold and silver). Gold usually occurs within tellurides, such as coloradoite, as a high-finess native metal.The quest for mining led to the discovery of telluride ores which were found to be associated with metals. Tellurides are ingrown into ores containing these precious metals and are also responsible for a significant amount of these metals being produced. Coloradoite, a member of the coordination subclass of tellurides, is a covalent compound that is isostructural with sphalerite (ZnS). Its chemical properties are highly instrumental in distinguishing it from other tellurides. It was first discovered in Colorado in 1877. Since then, other deposits have been found. Although it plays an important role in the geology of minerals, it can also be used for other purposes.

Free element

In chemistry, a free element is a chemical element that is not combined with or chemically bonded to other elements. Examples of elements which can occur as free elements include the oxygen molecule (O2) and carbon. All atoms of free elements have an oxidation number of 0.

Glossary of meteoritics

This is a glossary of terms used in meteoritics, the science of meteorites.

Gold extraction

Gold extraction refers to the processes required to extract gold from its ores. This may require a combination of comminution, mineral processing, hydrometallurgical, and pyrometallurgical processes to be performed on the ore.Gold mining from alluvium ores was once achieved by techniques associated with placer mining such as simple gold panning and sluicing, resulting in direct recovery of small gold nuggets and flakes. Placer mining techniques since the mid to late 20th century have generally only been the practice of artisan miners. Hydraulic mining was used widely in the Californian gold rush, and involved breaking down alluvial deposits with high-pressure jets of water. Hard rock ores have formed the basis of the majority of commercial gold recovery operations since the middle of the 20th century where open pit and or sub-surface mining techniques are used.

Once the ore is mined it can be treated as a whole ore using a dump leaching or heap leaching processes. This is typical of low-grade, oxide deposits. Normally, the ore is crushed and agglomerated prior to heap leaching. High grade ores and ores resistant to cyanide leaching at coarse particle sizes, require further processing in order to recover the gold values. The processing techniques can include grinding, concentration, roasting, and pressure oxidation prior to cyanidation.

IIAB meteorites

IIAB meteorites are a group of iron meteorites. Their structural classification ranges from hexahedrites to octahedrites. IIABs have the lowest concentration of nickel of all iron meteorite groups. All iron meteorites are derived from the metallic planetary cores of their respective parent bodies, but in the case of the IIABs the metallic magma separated to form not only this meteorite group but also the IIG group.

Korea Pathfinder Lunar Orbiter

The Korea Pathfinder Lunar Orbiter (KPLO) is a planned lunar orbiter by the Korea Aerospace Research Institute (KARI) of South Korea. The orbiter, its science payload and ground control infrastructure, are technology demonstrators. The orbiter will also be tasked with surveying lunar resources such as water ice, uranium, helium-3, silicon, and aluminium, and produce a topographic map to help select future lunar landing sites.

The mission is planned to be launched in December 2020 on a Falcon 9 rocket.

Meteoric iron

Meteoric iron, sometimes meteoritic iron, is a native metal found in meteorites and made from the elements iron and nickel mainly in the form of the mineral phases kamacite and taenite. Meteoric iron makes up the bulk of iron meteorites but is also found in other meteorites. Apart from minor amounts of telluric iron, meteoric iron is the only naturally occurring native metal of the element iron on the Earth's surface.

Natural material

A natural material is any product or physical matter that comes from plants, animals, or the ground. Minerals and the metals that can be extracted from them (without further modification) are also considered to belong into this category. Natural materials are used as building materials and clothing. Types include:

Biotic materials

Wood (rattan, bamboo, bark, etc.)

Natural fiber (silk, wool, cotton, flax, hemp, jute, kapok, kenaf, moss, etc.)

Inorganic material

Stone (flint, granite, obsidian, sandstone, sand, gems, glass, etc.)

Native metal (copper, iron, gold, silver, etc.)

Composites (clay, plasticine, etc.)

Other natural materials.

Soil

Platinum group

The platinum-group metals (abbreviated as the PGMs; alternatively, the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs)) are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5, 6 and 7).The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum. They have similar physical and chemical properties, and tend to occur together in the same mineral deposits. However they can be further subdivided into the iridium-group platinum-group elements (IPGEs: Os, Ir, Ru) and the palladium-group platinum-group elements (PPGEs: Rh, Pt, Pd) based on their behaviour in geological systems.The three elements above the platinum group in the periodic table (iron, nickel and cobalt) are all ferromagnetic, these being the only known transition metals with this property.

Silver

Silver is a chemical element with the symbol Ag (from the Latin argentum, derived from the Proto-Indo-European h₂erǵ: "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.

Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of the seven metals of antiquity, silver has had an enduring role in most human cultures.

Other than in currency and as an investment medium (coins and bullion), silver is used in solar panels, water filtration, jewellery, ornaments, high-value tableware and utensils (hence the term silverware), in electrical contacts and conductors, in specialized mirrors, window coatings, in catalysis of chemical reactions, as a colorant in stained glass and in specialised confectionery. Its compounds are used in photographic and X-ray film. Dilute solutions of silver nitrate and other silver compounds are used as disinfectants and microbiocides (oligodynamic effect), added to bandages and wound-dressings, catheters, and other medical instruments.

Tetrataenite

Tetrataenite is a native metal composed of chemically-ordered L10-type FeNi, recognized as a mineral in 1980. The mineral is named after its tetragonal crystal structure and its relation to the iron-nickel alloy, taenite. It is one of the mineral phases found in meteoric iron.

Zirconium

Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon (the word is related to Persian zargun (zircon;zar-gun, "gold-like" or "as gold")), the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur naturally, three of which are stable. Zirconium compounds have no known biological role.

Periodic table forms
Sets of elements
Elements
History
See also

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.