United States dollar
The United States dollar is the official currency of the United States and its territories per the United States Constitution since 1792. In practice, the dollar is divided into 100 smaller cent units, but is divided into 1000 mills for accounting; the circulating paper money consists of Federal Reserve Notes that are denominated in United States dollars. Since the suspension in 1971 of convertibility of paper U. S. currency into any precious metal, the U. S. dollar is, de facto, fiat money. As it is the most used in international transactions, the U. S. dollar is the world's primary reserve currency. Several countries use it as their official currency, in many others it is the de facto currency. Besides the United States, it is used as the sole currency in two British Overseas Territories in the Caribbean: the British Virgin Islands and Turks and Caicos Islands. A few countries use the Federal Reserve Notes for paper money, while still minting their own coins, or accept U. S. dollar coins. As of June 27, 2018, there are $1.67 trillion in circulation, of which $1.62 trillion is in Federal Reserve notes.
Article I, Section 8 of the U. S. Constitution provides that the Congress has the power "To coin money". Laws implementing this power are codified at 31 U. S. C. § 5112. Section 5112 prescribes the forms; these coins are both designated in Section 5112 as "legal tender" in payment of debts. The Sacagawea dollar is one example of the copper alloy dollar; the pure silver dollar is known as the American Silver Eagle. Section 5112 provides for the minting and issuance of other coins, which have values ranging from one cent to 100 dollars; these other coins are more described in Coins of the United States dollar. The Constitution provides that "a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time"; that provision of the Constitution is made specific by Section 331 of Title 31 of the United States Code. The sums of money reported in the "Statements" are being expressed in U. S. dollars. The U. S. dollar may therefore be described as the unit of account of the United States.
The word "dollar" is one of the words in the first paragraph of Section 9 of Article I of the Constitution. There, "dollars" is a reference to the Spanish milled dollar, a coin that had a monetary value of 8 Spanish units of currency, or reales. In 1792 the U. S. Congress passed a Coinage Act. Section 9 of that act authorized the production of various coins, including "DOLLARS OR UNITS—each to be of the value of a Spanish milled dollar as the same is now current, to contain three hundred and seventy-one grains and four sixteenth parts of a grain of pure, or four hundred and sixteen grains of standard silver". Section 20 of the act provided, "That the money of account of the United States shall be expressed in dollars, or units... and that all accounts in the public offices and all proceedings in the courts of the United States shall be kept and had in conformity to this regulation". In other words, this act designated the United States dollar as the unit of currency of the United States. Unlike the Spanish milled dollar, the U.
S. dollar is based upon a decimal system of values. In addition to the dollar the coinage act established monetary units of mill or one-thousandth of a dollar, cent or one-hundredth of a dollar, dime or one-tenth of a dollar, eagle or ten dollars, with prescribed weights and composition of gold, silver, or copper for each, it was proposed in the mid-1800s that one hundred dollars be known as a union, but no union coins were struck and only patterns for the $50 half union exist. However, only cents are in everyday use as divisions of the dollar. XX9 per gallon, e.g. $3.599, more written as $3.599⁄10. When issued in circulating form, denominations equal to or less than a dollar are emitted as U. S. coins while denominations equal to or greater than a dollar are emitted as Federal Reserve notes. Both one-dollar coins and notes are produced today, although the note form is more common. In the past, "paper money" was issued in denominations less than a dollar and gold coins were issued for circulation up to the value of $20.
The term eagle was used in the Coinage Act of 1792 for the denomination of ten dollars, subsequently was used in naming gold coins. Paper currency less than one dollar in denomination, known as "fractional currency", was sometimes pejoratively referred to as "shinplasters". In 1854, James Guthrie Secretary of the Treasury, proposed creating $100, $50 and $25 gold coins, which were referred to as a "Union", "Half Union", "Quarter Union", thus implying a denomination of 1 Union = $100. Today, USD notes are made from cotton fiber paper, unlike most common paper, made of wood fiber. U. S. coins are produced by the United States Mint. U. S. dollar banknotes are printed by the Bureau of Engraving and Printing and, since 1914, have been issued by t
Aluminium or aluminum is a chemical element with symbol Al and atomic number 13. It is a silvery-white, soft and ductile metal in the boron group. By mass, aluminium makes up about 8% of the Earth's crust; the chief ore of aluminium is bauxite. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. Aluminium is remarkable for its low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the aerospace industry and important in transportation and building industries, such as building facades and window frames; the oxides and sulfates are the most useful compounds of aluminium. Despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals; because of these salts' abundance, the potential for a biological role for them is of continuing interest, studies continue.
Of aluminium isotopes, only 27Al is stable. This is consistent with aluminium having an odd atomic number, it is the only aluminium isotope that has existed on Earth in its current form since the creation of the planet. Nearly all the element on Earth is present as this isotope, which makes aluminium a mononuclidic element and means that its standard atomic weight equates to that of the isotope; the standard atomic weight of aluminium is low in comparison with many other metals, which has consequences for the element's properties. All other isotopes of aluminium are radioactive; the most stable of these is 26Al and therefore could not have survived since the formation of the planet. However, 26Al is produced from argon in the atmosphere by spallation caused by cosmic ray protons; the ratio of 26Al to 10Be has been used for radiodating of geological processes over 105 to 106 year time scales, in particular transport, sediment storage, burial times, erosion. Most meteorite scientists believe that the energy released by the decay of 26Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago.
The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. An aluminium atom has 13 electrons, arranged in an electron configuration of 3s23p1, with three electrons beyond a stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Aluminium can easily surrender its three outermost electrons in many chemical reactions; the electronegativity of aluminium is 1.61. A free aluminium atom has a radius of 143 pm. With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure, aluminium atoms form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; this crystal system is shared by some other metals, such as copper. Aluminium metal, when in quantity, is shiny and resembles silver because it preferentially absorbs far ultraviolet radiation while reflecting all visible light so it does not impart any color to reflected light, unlike the reflectance spectra of copper and gold.
Another important characteristic of aluminium is its low density, 2.70 g/cm3. Aluminium is a soft, lightweight and malleable with appearance ranging from silvery to dull gray, depending on the surface roughness, it is nonmagnetic and does not ignite. A fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation; the yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has stiffness of steel, it is machined, cast and extruded. Aluminium atoms are arranged in a face-centered cubic structure. Aluminium has a stacking-fault energy of 200 mJ/m2. Aluminium is a good thermal and electrical conductor, having 59% the conductivity of copper, both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity, with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss.
Aluminium is the most common material for the fabrication of superconducting qubits. Aluminium's corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the bare metal is exposed to air preventing further oxidation, in a process termed passivation; the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts in the presence of dissimilar metals. In acidic solutions, aluminium reacts with water to form hydrogen, in alkaline ones to form aluminates—protective passivation under these conditions is negligible; because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium. However, because
The United States large cent was a coin with a face value of 1/100 of a United States dollar. Its nominal diameter was 11⁄8 inch; the first official mintage of the large cent was in 1793, its production continued until 1857, when it was replaced by the modern-size one-cent coin. Large cents were made of nearly pure copper, or copper as pure as it emerged from smelting, without any deliberate addition of other metals. First struck in 1793, the large cent was coined every year from 1793 to 1857 except 1815; the wartime embargo against shipments made it so the mint could not get any new copper planchets, which were imported from Great Britain, to strike coins. The mint made do with what supply it had and struck coins into 1815. After the war ended in 1815, the mint wasted no time in ordering new planchets. For an unknown reason no coins were dated 1815 from the supply. In addition to the copper shortage, people hoarded precious metals during the war; the Philadelphia Mint produced all large cents.
This made the coins bulky and heavy, bigger than modern-day U. S. Quarters; the obverse featured a bust of Liberty with a reverse of a ring of chains. Henry Voigt's design was universally criticized in its time for its unattractiveness and perceived allusion to slavery, it bears the distinction, however, of being the first official coinage minted by the United States federal government on its own equipment and premises. 36,103 were minted. Its low survival rate, in addition to its small mintage, coupled with being the first regular federal issue and a one-year design and type, has created an strong demand from generations of numismatists; as a result, all surviving specimens command high prices ranging from $2,000-$3,000 in the absolute lowest state of preservation to over $500,000 in the highest. The Mint caved in to the intense ridicule in 1793, Mint Director David Rittenhouse ordered Adam Eckfeldt to revise the obverse and reverse designs. Liberty's bust was redesigned with longer, wilder hair, the chain was removed from the reverse in favor of a wreath.
Scholars are undecided as to what plant or plants are depicted in the wreath, with several varieties extant. Total mintage of the wreath reverse numbered about 63,000 pieces. Rittenhouse was dissatisfied with Eckfeldt's designs, with the criticism of the Chain cents fresh in his mind, he hired Joseph Wright to do yet another redesign in the denomination's troubled first year. Wright's design "tamed" her wild hair; the Phrygian cap was added as an ancient symbol of freedom. The reverse design was revised to a recognizable laurel wreath, future Chief Engraver Robert Scot had a hand in several minor revisions to the design over the next three years; this design was more successful and it was continued into 1796. In 1795, planchets became too thin for the edge lettering because of a weight reduction, so the mint stopped edge lettering on the cent, the rest of these coins were made with a plain edge. Four coins from 1795 are known to have a reeded edge. Robert Scot redesigned the whole of United States coinage for 1796, applying a new design featuring a bust of Liberty wearing a drapery at the neckline and a ribbon in her flowing hair.
The reverse design now featured an olive wreath. As with earlier types, several minor revisions to the design were made in the first few years, with the final 1797 design lasting through the end of the type in 1807. John Reich, assistant to Chief Engraver Scot, was appointed by new Mint Director Robert Patterson to redesign Scot's Draped Bust cent; the so-called "Classic Head" derives its name from the fillet worn by Liberty on the obverse, though the fillet was worn only by male athletes in ancient Greece. The copper used during the years in which Classic Head cents were minted was of a higher quality, containing less metallic impurity, they were softer and more prone to wear and corrode more than issues before or after. As a result, high-grade specimens are difficult to obtain and fetch strong premiums when they appear on market with original red or red-brown mint luster; as a response to public criticism of the Classic Head, the Mint assigned Chief Engraver Scot to redesign the cent in 1816.
This newest design enlarged the obverse portrait, giving Liberty a much more mature look, surrounded the portrait with stars along the outer edge of the coin. The "Matron head" design was modified in 1835 to give Liberty a younger look and matron head cents continued to be made until 1839. Facing more negative public reaction, the Coronet cents were redesigned in 1835 by new Chief Engraver Christian Gobrecht; this last major change to the coin updated the obverse by giving Liberty a slimmer, more youthful appearance. Minor tweaks continued through 1843, the 1843 design prevailed through the end of mintage in 1857; some 11 years after the large cent was discontinued, a mint employee coined several large cents dated 1868 certainly for sale as instant rarities to numismatists. Fewer than a dozen of these unofficial issues, struck in both bronze and copper-nickel, are known to survive. United States dollar Mill Complete US Large Cent information by type. Histories, mintages, diameters, metal contents, edge designs and more.
Large Cent Pictures Images of Large Cents at the American Numismatic Society
Copper is a chemical element with symbol Cu and atomic number 29. It is a soft and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals; this led to early human use in several regions, from c. 8000 BC. Thousands of years it was the first metal to be smelted from sulfide ores, c. 5000 BC, the first metal to be cast into a shape in a mold, c. 4000 BC and the first metal to be purposefully alloyed with another metal, tin, to create bronze, c. 3500 BC. In the Roman era, copper was principally mined on Cyprus, the origin of the name of the metal, from aes сyprium corrupted to сuprum, from which the words derived and copper, first used around 1530.
The encountered compounds are copper salts, which impart blue or green colors to such minerals as azurite and turquoise, have been used and as pigments. Copper used in buildings for roofing, oxidizes to form a green verdigris. Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found in the liver and bone; the adult body contains between 2.1 mg of copper per kilogram of body weight. Copper and gold are in group 11 of the periodic table; the filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds.
Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are weak. This observation explains the low high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms; the softness of copper explains its high electrical conductivity and high thermal conductivity, second highest among pure metals at room temperature. This is because the resistivity to electron transport in metals at room temperature originates from scattering of electrons on thermal vibrations of the lattice, which are weak in a soft metal; the maximum permissible current density of copper in open air is 3.1×106 A/m2 of cross-sectional area, above which it begins to heat excessively. Copper is one of a few metallic elements with a natural color other than silver.
Pure copper acquires a reddish tarnish when exposed to air. The characteristic color of copper results from the electronic transitions between the filled 3d and half-empty 4s atomic shells – the energy difference between these shells corresponds to orange light; as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. Copper does not react with water, but it does react with atmospheric oxygen to form a layer of brown-black copper oxide which, unlike the rust that forms on iron in moist air, protects the underlying metal from further corrosion. A green layer of verdigris can be seen on old copper structures, such as the roofing of many older buildings and the Statue of Liberty. Copper tarnishes when exposed to some sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper. 63Cu and 65Cu are stable, with 63Cu comprising 69% of occurring copper. The other isotopes are radioactive, with the most stable being 67Cu with a half-life of 61.83 hours.
Seven metastable isotopes have been characterized. Isotopes with a mass number above 64 decay by β−, whereas those with a mass number below 64 decay by β+. 64Cu, which has a half-life of 12.7 hours, decays both ways.62Cu and 64Cu have significant applications. 62Cu is used in 62Cu-PTSM as a radioactive tracer for positron emission tomography. Copper is produced in massive stars and is present in the Earth's crust in a proportion of about 50 parts per million. In nature, copper occurs in a variety of minerals, including native copper, copper sulfides such as chalcopyrite, digenite and chalcocite, copper sulfosalts such as tetrahedite-tennantite, enargite, copper carbonates such as azurite and malachite, as copper or copper oxides such as cuprite and tenorite, respectively; the largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal
Silver center cent
The silver center cent is an American pattern coin, one of the precursors to the large cent and an early example of a bimetallic coin. Less than a dozen specimens are known to exist today, they fetch substantial prices; that price was eclipsed by an example graded PCGS MS61 offered at auction in April 2012, with a price tag of more than $1 million. During the early years of the American republic, there was a general consensus that the intrinsic bullion value of the new nation's coinage should be equal to its face value; some merchants would refuse to accept coins. For most denominations, bullion parity was achieved by producing the coins in a gold or silver alloy. However, the Coinage Act of 1792 specified that the cent was to consist of 11 pennyweight of pure copper; such a weight, needed to maintain intrinsic value, would have been too heavy for practical everyday use. U. S. Secretary of State Thomas Jefferson suggested an alternative: a coin made of an alloy, copper, but that included enough silver to give a reasonably-sized coin an intrinsic value of one cent.
This billon alloy was considered by the U. S. Mint, but U. S. Treasury Secretary Alexander Hamilton feared that it would be too susceptible to counterfeiting, since its appearance differed little from that of pure copper. In 1792, the Mint's chief coiner, Henry Voight, hit upon a solution: a copper planchet smaller than that of a modern quarter, with a small silver "plug" inserted in a center hole during the striking process; the silver plug would have been worth 3⁄4¢ at contemporary bullion prices, while the copper planchet added an additional 1⁄4¢ of intrinsic value. Several such coins were produced as test pieces; the additional labor required for these bimetallic coins proved unsuitable for mass production, the large cent, produced for circulation starting in 1793 consisted of 208 grains of 100% copper. The obverse of the silver center cent features a Liberty head with flowing hair; the date appears below the portrait, the words "LIBERTY PARENT OF SCIENCE & INDUST." are inscribed in a circular pattern around the central devices.
The reverse design consists of a wreath with the words "ONE CENT" in the center, the fraction "1/100" below. Surrounding the wreath, "UNITED STATES OF AMERICA" is inscribed
History of the United States dollar
The history of the United States Dollar refers to more than 240 years since the Continental Congress of the United States authorized the issuance of Continental Currency in 1775. On April 2, 1792, the United States Congress created the United States dollar as the country's standard unit of money; the term dollar had been in common usage since the colonial period when it referred to eight-real coin used by the Spanish throughout New Spain. After the American Revolutionary War began in 1775, the Continental Congress began issuing paper money known as Continental currency, or Continentals. Continental currency was denominated in dollars from $1⁄6 to $80, including many odd denominations in between. During the Revolution, Congress issued $241,552,780 in Continental currency. By the end of 1778, this Continental currency retained only between 1⁄5 to 1⁄7 of its original face value. By 1780, Continental bills – or Continentals – were worth just 1⁄40 of their face value. Congress tried to reform the currency by removing the old bills from circulation and issuing new ones, but this met with little to no success.
By May 1781, Continentals had become so worthless. Benjamin Franklin noted that the depreciation of the currency had, in effect, acted as a tax to pay for the war. In the 1790s, after the ratification of the United States Constitution, Continentals could be exchanged for treasury bonds at 1% of face value. Congress appointed Robert Morris to be Superintendent of Finance of the United States following the collapse of Continental currency. In 1782, Morris advocated the creation of the first financial institution chartered by the United States; the Bank of North America was funded in part by bullion coin, loaned to the United States by France. Morris helped finance the final stages of the war by issuing promissory notes in his name, backed by his own money; the Bank of North America issued notes convertible into gold or silver. On July 6, 1785, the Continental Congress of the United States authorized the issuance of a new currency, the US dollar. However, runaway inflation and the collapse of the Continental currency prompted delegates at the Constitutional Convention in Philadelphia in 1787 to include the gold and silver clause in the United States Constitution, preventing individual States from issuing their own bills of credit.
Article One states they were prohibited to "make any Thing but gold and silver Coin a Tender in Payment of Debts." Some people use this clause to argue. The United States Mint was created by Congress following the passing of the Coinage Act of 1792, it was tasked with producing and circulating coinage. The first Mint building was in Philadelphia the capital of the United States; the Mint was placed within the Department of State, until the Coinage Act of 1873 when it became part of the Department of the Treasury. The Mint had the authority to convert any precious metals into standard coinage for anyone's account with no seigniorage charge beyond refining costs. After the creation of the U. S. dollar, the fledgling American administration of President George Washington turned its attention to monetary issues again in the early 1790s, under the leadership of Alexander Hamilton, the Secretary of the Treasury at the time. Congress acted on Hamilton's recommendations, with the Coinage Act of 1792 that established the dollar as the basic unit of account for the United States.
The word dollar is derived from Low Saxon cognate of the High German Thaler. The most circulated and available currency, used by common Americans, at this time, was the Spanish Peso known as the "Spanish milled dollar", valued for its high silver content. In the early 19th century, the intrinsic value of gold coins rose relative to their nominal equivalent in silver coins, resulting in the removal from commerce of nearly all gold coins, their subsequent private melting. Therefore, in the Coinage Act of 1834, the 15:1 ratio of silver to gold was changed to a 16:1 ratio by reducing the weight of the nation's gold coinage; this created a new U. S. dollar, backed by 1.50 grams of gold. However, the previous dollar had been represented by 1.60 g of gold. The result of this revaluation, the first devaluation of the U. S. dollar, was that the value in gold of the dollar was reduced by 6%. Moreover, for a time, both gold and silver coins were useful in commerce. In 1853, the weights of U. S. silver coins were reduced.
This had the effect of placing the nation on the gold standard. The retained weight in the dollar coin was a nod to bimetallism, although it had the effect of further driving the silver dollar coin from commerce. Foreign coins, including the Spanish dollar, were widely used, as legal tender, until 1857. With the enactment of the National Banking Act of 1863—during the American Civil War—and its versions that taxed states' bonds and currency out of existence, the dollar became the sole currency of the United States and remains so today. During the 19th century the dollar was less accepted around the world than the British pound. Nellie Bly carried Bank of England notes on her 1889-1890 trip around the world in 72 days. Traveling east from New York, she did not see American money until she found $20 gold pieces used as jewelry in Colombo. In 1878, the Bland-Allison Act was enacted to provide for
Penny (United States coin)
The United States one-cent coin called the penny, is a unit of currency equaling one one-hundredth of a United States dollar. The cent's symbol is ¢, its obverse has featured the profile of President Abraham Lincoln since 1909, the centennial of his birth. From 1959 to 2008, the reverse featured the Lincoln Memorial. Four different reverse designs in 2009 honored Lincoln's 200th birthday and a new, "permanent" reverse – the Union Shield – was introduced in 2010; the coin is 0.75 inches in diameter and 0.0598 inches in thickness. Its weight has varied, depending upon the composition of metals used in its production; the U. S. Mint's official name for the coin is "cent" and the U. S. Treasury's official name is "one cent piece"; the colloquial term penny derives from the British coin of the same name, the pre-decimal version of which had a similar place in the British system. In American English, pennies is the plural form. In the early 2010s the price of metal used to make pennies rose to a noticeable cost to the mint which peaked at a $0.02 for $0.01 ratio.
This pushed the mint to look for alternative metals again for the coin, brought the penny debate into more focus. There are no firm plans to eliminate the penny as arguments for and against the coin continue to be debated. In honor of Lincoln's 200th anniversary, special 2009 cents were minted for collectors in the same composition as the 1909 coins; the isotope composition of early coins spanning the period 1828 to 1843 reflects the copper from Cornish ores from England, while coins after 1850 reflect the Keweenaw Peninsula, Michigan ores, a finding consistent with historical records. In 1943, at the peak of World War II, zinc-coated steel cents were made for a short time because of war demands for copper. A few copper cents from 1943 were produced from the 1942 planchets remaining in the bins; some 1944 steel cents have been confirmed. From 1944 to 1946, salvaged ammunition shells made their way into the minting process, it was not uncommon to see coins featuring streaks of brass or having a darker finish than other issues.
During the early 1970s, the price of copper rose to the point where the cent contained one cent's worth of copper. This led the Mint to test alternative metals, including aluminum and bronze-clad steel. Aluminum was chosen, over 1.5 million of these pennies were struck and ready for public release before being rejected. The proposed aluminum pennies were rejected for two reasons: vending machine owners complained the coins would cause mechanical problems. One aluminum cent was donated to the Smithsonian Institution; the cent's composition was changed in 1982 because the value of the copper in the coin started to rise above one cent. Some 1982 pennies used the 97.5% zinc composition, while others used the 95% copper composition. With the exception of 2009 bicentennial cents minted for collectors, United States cents minted after 1982 have been zinc with copper plating. In Fiscal Year 2013, the average one-cent piece minted cost the U. S. Mint 1.83 cents, down from 2.41 cents apiece in FY 2011. The bronze and copper cents can be distinguished from the newer zinc cents by dropping the coins on a solid surface.
The predominantly zinc coins make a lower-pitched "clunk", while the copper coins produce a higher-pitched ringing sound. In addition, a full 50-cent roll of pre-1982/3 coins weighs 5.4 oz compared to a post-1982–83 roll which weighs 4.4 oz. Mintage figures for the penny can be found at United States cent mintage figures; the coin has gone through several designs over its two-hundred-year time frame. Until 1857 it was about the size of the current U. S. dollar coins. The following types of cents have been produced: Large cents: Flowing Hair Chain 1793 Flowing Hair Wreath 1793 Liberty Cap 1793–1796 Draped bust 1796–1807 Classic Head 1808–1814 Coronet 1816–1839 Braided Hair 1839–1857, 1868 Small cents: Flying Eagle cent Indian Head cent Lincoln cent Lincoln Wheat Lincoln Memorial Lincoln Bicentennial 4 reverse designs Lincoln Union Shield Throughout its history, the Lincoln cent has featured several typefaces for the date, but most of the digits have been old-style numerals, except with the 4 and 8 neither ascending nor descending.
The only significant divergence is that the small 3 was non-descending in the early history, before switching to a descending, large 3 for just one year in 1934 and permanently in 1943. The digit 5 was small and non-descending up to 1945 from 1950 and on, it became a large descending 5. From 1959 until 2008, the Lincoln Memorial was shown on the reverse of the United States cent; because the Lincoln Memorial was shown in sufficient detail to discern the statue of Lincoln on the reverse of cent, Abraham Lincoln was at that time the only person to be depicted on both the obverse and reverse of the same United States coin. In 1999, the New Jersey state quarter was released, which depicts George Washington on both sides, crossing the Delaware River on the reverse side and in profile on the obverse. (The state quarter for South Dakota, released in 2006 features Washington on both sides: the typical profile on the obverse, Washington within Mount Rushmore on the re