Troy weight

Troy weight is a system of units of mass that originated in 15th-century England[1], and is primarily used today in the precious metals industry. Its units are the grain, pennyweight (24 grains), troy ounce (20 pennyweights), and troy pound (12 troy ounces). The grain is the same grain used in the more common avoirdupois system. By contrast, the troy ounce is heavier than the avoirdupois ounce, while the troy pound is lighter than the avoirdupois pound.

1 oz of fine gold
Troy ounce is a traditional unit of gold weight.
American Platinum Eagle 2008 Proof Rev
1 troy ounce (1.097 avoirdupois ounces, 31.1 g) coin example (Platinum Eagle)
Ingots of Ge, Fe, Al, Re, Os, one troy ounce each (2)
One troy ounce (1.1 oz; 31 g) samples of germanium, iron, aluminium, rhenium and osmium
A Good Delivery silver bar weighing 1,000 troy ounces (69 lb; 31 kg)


Troy weight probably takes its name from the French market town of Troyes in France where English merchants traded at least as early as the early 9th century.[2][3] The name "troy" is first attested in 1390, describing the weight of a platter, in an account of the travels in Europe of the Earl of Derby.[2][4]

Charles Moore Watson (1844–1916) proposes an alternative etymology: The Assize of Weights and Measures (also known as Tractatus de Ponderibus et Mensuris), one of the statutes of uncertain date from the reign of either Henry III or Edward I, thus before 1307, specifies "troni ponderacionem"—which the Public Record Commissioners translate as "troy weight". The word "troni" refers to markets. Watson finds the dialect word "troi", meaning a balance in Wright's Dialect Dictionary. Troy weight referred to the tower system; the earliest reference to the modern troy weights is in 1414.[5][6]


Many aspects of the troy weight system were indirectly derived from the Roman monetary system. The Romans used bronze bars of varying weights as currency. An aes grave ("heavy bronze") weighed one pound. One twelfth of an aes grave was called an uncia, or in English, an "ounce". Before the adoption of the metric system, many systems of troy weights were in use in various parts of Europe, among them Holland troy, Paris troy, etc.[7] Their values varied from one another by up to several percentage points. Troy weights were first used in England in the 15th century, and were made official for gold and silver in 1527.[1] The British Imperial system of weights and measures (also known as Imperial units) was established in 1824, prior to which the troy weight system was a subset of pre-Imperial English units.

The troy ounce in use today is essentially the same as the British Imperial troy ounce (1824–1971), adopted as an official weight standard for United States coinage by Act of Congress on May 19, 1828.[8] The British Imperial troy ounce (known more commonly simply as the imperial troy ounce) was based on, and virtually identical with, the pre-1824 British troy ounce and the pre-1707 English troy ounce. (1824 was the year the British Imperial system of weights and measures was adopted, 1707 was the year of the Act of Union which created the Kingdom of Great Britain.) Troy ounces have been used in England since about 1400 and the English troy ounce was officially adopted for coinage in 1527. Before that time, various sorts of troy ounces were in use on the continent.[9]

The troy ounce and grain were also part of the apothecaries' system. This was long used in medicine, but has now been largely replaced by the metric system (milligrams).[10]

The only troy weight in widespread use today is the British Imperial troy ounce and its American counterpart. Both are currently based on a grain of 0.06479891 gram (exact, by definition), with 480 grains to a troy ounce (compared with ​437 12 grains for an ounce avoirdupois).

The British Empire abolished the 12-ounce troy pound in the 19th century, though it has been retained (although rarely used) in the American system.


The origin of the troy weight system is unknown. Although the name probably comes from the Champagne fairs at Troyes, in northeastern France,[11] the units themselves may be of more northern origin. English troy weights were nearly identical to the troy weight system of Bremen. (The Bremen troy ounce had a mass of 480.8 British Imperial grains.)[9]

An alternative suggestion is that the weights come from the Muslim domains by way of the Gold Dirhem (47.966 British Imperial grains), in the manner that King Offa's weights were derived from the silver Dirhem (about 45.0 British grains).

According to Watson, troy relates to a dialect word troi (balance). Then troy weight is a style of weighing, like auncel or bismar weights, or other kindred methods. The troy weight then refers to weighing of small precious or potent goods, such as bullion and medicines.[5]

Use in other countries

Troy ounces are still often used in precious metal markets in countries that otherwise use International System of Units (SI),[12][13] except in East Asia.[14] The People's Bank of China, in particular, which has never historically used troy measurements, has begun issuing Gold Pandas minted according to SI weights.

Units of measurement

Comparison of pounds
Chart comparing the mass (in grams) of tower, Troy, merchant, avoirdupois and London pounds. Each colored block represents one ounce (gold=Troy, blue= avoirdupois, purple=tower)

Troy pound

The troy pound is 5 760 grains (≈ 373.24 g, 12 oz t), while an avoirdupois pound is approximately 21.53% heavier at 7 000 grains (≈ 453.59 g).

Troy ounce (oz t)

Because of the International yard and pound agreement, one troy ounce (oz t) equals exactly 31.103 476 8 grams. It also equals 1.09714286 avoirdupois ounces, or exactly ​192175, about 10% larger.

The international yard and pound agreement did not define any troy weights. Rather, it defined the avoirdupois pound in metric terms, from which we can derive an exact value for the troy ounce. Specifically, it defined one pound as 0.45359237 kg. We can derive an exact value for the troy ounce as follows:

1 lb = 0.45359237 kg = 453.59237 grams

An avoirdupois pound also equals 7000 grains (the international yard and pound agreement did not change the grain values of non-metric units).

1 lb = 7000 grains
7000 grains = 453.59237 grams
1 grain = 453.59237 grams/7000 grains = 0.06479891 g/gr
1 troy ounce = 480 grains × 0.06479891 g/gr = 31.1034768 grams

Pennyweight (dwt)

The pennyweight symbol is dwt. There are 24 grains in 1 dwt, and 20 dwt in one troy ounce. Because there were 12 troy ounces in the old troy pound, there would have been 240 pennyweights to the pound—the basis of the fact that the old British pound sterling of currency contained 240 pence. (However, prior to 1526, English pound sterling was based on the tower pound, which is ​1516 of a troy pound.) The d in dwt stands for denarius, the ancient Roman coin that equates loosely to a penny. The symbol d for penny can be recognized in the notation for British pre-decimal pennies, in which pounds, shillings, and pence were indicated using the symbols £, s, and d, respectively. For example, £6 11s 8d indicated six pounds, eleven shillings, and eight pence.

Mint weights

Mint weights, also known as moneyers' weights were legalised by Act of Parliament dated 17 July 1649 entitled An Act touching the monies and coins of England. A grain is 20 mites, a mite is 24 droits, a droit is 20 perits, a perit is 24 blanks.[15][16]

Scottish system

In Scotland, the Incorporation of Goldsmiths of the City of Edinburgh used a system in multiples of sixteen. (See Assay-Master's Accounts, 1681–1702, on loan from the Incorporation to the National Archives of Scotland.) Thus, there were 16 drops to the troy ounce, 16 ounces to the troy pound, and 16 pounds to the troy stone. The Scots had several other ways of measuring precious metals and gems, but this was the common usage for gold and silver.

The Pound was 7716 British Imperial grains, but after the union, rounded to 7680 BI grains. This divides to 16 ounces, each of 16 drops, each of 30 grains. The rounding makes the ounce and grain equal to the English standard.

Dutch system

The Dutch troy system is based on a Mark, of 8 Ounces, the ounce of 20 Engels (pennyweight), the Engel of 32 As. The mark was rated as 3798 Grains, English troy, or 246.084 metric grams. The divisions are identical to the tower system.[17]


Unit Grains Grams (exact)
Troy pound (12 troy ounces) 5,760 373.24172 160
Troy ounce (20 pennyweights) 480 31.10347 680
Pennyweight 24 1.55517 384
Grain 1 0.06479 891
English pounds
Unit Pounds Ounces Grains Metric
Avdp. Troy Tower Merchant London Metric Avdp. Troy Tower Troy Tower g kg
Avoirdupois 1 175/144 = 1.21527 35/27 = 1.296 28/27 = 1.037 35/36 = 0.972 ≈ 0.9072 16 14 7/12 = 14.583 15 5/9 = 15.5 7000 09955 5/9 ≈ 454 5/11
Troy 144/175 ≈ 0.8229 1 16/15 = 1.06 64/75 = 0.853 4/5 = 0.8 ≈ 0.7465 13 29/175 ≈ 13.17 12 12 4/5 = 12.8 5760 08192 ≈ 373 3/8
Tower 27/35 ≈ 0.7714 15/16 = 0.9375 1 4/5 = 0.8 3/4 = 0.75 ≈ 0.6998 12 12/35 ≈ 12.34 11 1/4 = 11.25 12 5400 07680 ≈ 350 7/20
Merchant 27/28 ≈ 0.9643 75/64 = 1.171875 5/4 = 1.25 1 15/16 = 0.9375 ≈ 0.8748 15 3/7 ≈ 15.43 14 1/16 = 14.0625 15 6750 09600 ≈ 437 7/16
London 36/35 ≈ 1.029 5/4 = 1.25 4/3 = 1.3 16/15 = 1.06 1 ≈ 0.9331 16 16/35 ≈ 16.46 15 16 7200 10240 ≈ 467 7/15
Metric ≈ 1.1023 ≈ 1.3396 ≈ 1.4289 ≈ 1.1431 ≈ 1.0717 1 ≈ 17.64 ≈ 16.08 ≈ 17.15 7716 10974 = 500 = 1/2

The troy system was used in the apothecaries' system, but with different further subdivisions.

Relationship to British coinage

King Offa's currency reform replaced the sceat with the silver penny. This coin was derived from half of a silver dirhem. The weights were then derived by a count of coins, by a mix of Charlemagne and Roman systems. A shilling was set to twelve pence, an ounce to twenty pence, and a pound to twelve ounces or twenty shillings. The penny was quite a lot of money, so weight by coins was not a general practice.

Later kings debased the coin, both in weight and fineness. The original pound divided was the tower pound of 5400 grains, but a later pound of 5760 grains displaced it. Where once 240 pence made a tower pound (and 256 make a troy pound), by the time of the United Kingdom Weights and Measures Act of 1824, a troy pound gives 792 silver pence, still minted as such as Maundy Money.

Sterling originally referred to the Norman silver penny of the late 11th century. The coin was minted to a fineness of 11 oz, 2 dwt (in the pound), or 925 Millesimal fineness.

See also


  1. ^ a b Hallock, William; Wade, Herbert Treadwell (1906). Outlines of the evolution of weights and measures and the metric system. London: The Macmillan company. p. 34. Archived from the original on 5 January 2014. Retrieved 14 August 2012.
  2. ^ a b "troy, n.2". Oxford English Dictionary. Oxford, England: Oxford University Press. June 2012. The received opinion is that it took its name from a weight used at the fair of Troyes in France
  3. ^ Partridge, Eric (1958). "Trojan". Origins: A Short Etymological Dictionary of Modern English. London: Routledge and Kegan Paul. p. 3566. OCLC 250202885. …the great fairs established for all Europe the weight-standard Troyes, whence…Troy
  4. ^ Smith, L. Toulmin (1894). Expeditions to Prussia and the Holy Land Made by Henry Earl of Derby (afterwards King Henry IV.) in the Years 1390-1 and 1392-3. London: Camden Society. Archived from the original on 3 July 2014. Retrieved 14 August 2012.
  5. ^ a b Watson, Charles Moore (1910). British weights and measures as described in the laws of England from Anglo-Saxon times. London: John Murray. p. 82. OCLC 4566577. Archived from the original on 2016-04-01.
  6. ^ Wright, Joseph (1898). The English dialect dictionary. 6. Oxford: English Dialect Society. p. 250. OCLC 63381077.
  7. ^ Patrick Kelly, LL.D. - The Universal Cambist and Commercial Instructor, Vol. 1 Archived 2017-03-27 at the Wayback Machine p. 20 (1811)
  8. ^ Hallock, Wade (1906). Outlines of the evolution of weights and measures and the metric system. The Macmillan company. p. 119.
  9. ^ a b Zupko, Ronald Edward (1977). British Weights and Measures: A History from Antiquity to the Seventeenth Century. University of Wisconsin Press. pp. 28–9. ISBN 978-0-299-07340-4.
  10. ^ "Troy Ounce". WordNet 3.0, Princeton University. Archived from the original on 2008-02-26. Retrieved 2008-01-10.
  11. ^ Smith, Adam (1809). An Inquiry Into the Nature and Causes of the Wealth of Nations, Volume 1. 1. London: T. Hamilton. p. 35. Archived from the original on 2017-02-22. The French livre contained, in the time of Charlemagne, a pound, Troyes weight, of silver of a known finess. The fair of Troyes in Champaign was at that time frequented by all the nations of Europe, and the weights and measures of so famous a market were generally known and esteemed.
  12. ^ "Börse Frankfurt: Aktien, Kurse, Charts und Nachrichten". Archived from the original on 1 November 2015. Retrieved 28 April 2018.
  13. ^ "Units of Measure - The Perth Mint". Archived from the original on 2015-09-24.
  14. ^ "Do grams or ounces win?". Archived from the original on 2016-05-06.
  15. ^ Philological Society (Great Britain) (1891). A new English dictionary on historical principles: founded mainly on the materials collected by the Philological Society. Clarendon Press. p. 675. Archived from the original on 27 June 2014. Retrieved 21 April 2012.
  16. ^ Miege, Guy (1738). The Present State of Great Britain and Ireland. J. Brotherton, A. Bettesworth and C. Hitch, G. Strahan, W. Mears, R. Ware, E. Symon, and J. Clark. p. 307. Archived from the original on 28 April 2018. Retrieved 6 June 2017.
  17. ^ Kelly, Patric (1835). Universal Cambist. London.
Avoirdupois system

The avoirdupois system (; abbreviated avdp) is a measurement system of weights which uses pounds and ounces as units. It was first commonly used in the 13th century and was updated in 1959.In 1959, by international agreement, the definitions of the pound and ounce became standardized in countries which use the pound as a unit of mass. The International Avoirdupois Pound was then created. It is the everyday system of weights used in the United States. It is still used, in varying degrees, in everyday life in the United Kingdom, Canada, and some other former British colonies, despite their official adoption of the metric system.

The avoirdupois weight system's general attributes were originally developed for the international wool trade in the Late Middle Ages, when trade was in recovery. It was historically based on a physical standardized pound or "prototype weight" that could be divided into 16 ounces. There were a number of competing measures of mass, and the fact that the avoirdupois pound had three even numbers as divisors (half and half and half again) may have been a cause of much of its popularity, so that the system won out over systems with 12 or 10 or 15 subdivisions. The use of this unofficial system gradually stabilized and evolved, with only slight changes in the reference standard or in the prototype's actual mass.

Over time, the desire not to use too many different systems of measurement allowed the establishment of "value relationships", with other commodities metered and sold by weight measurements such as bulk goods (grains, ores, flax) and smelted metals; so the avoirdupois system gradually became an accepted standard through much of Europe.In England, Henry VII authorized its use as a standard, and Queen Elizabeth I acted three times to enforce a common standard, thus establishing what became the Imperial system of weights and measures. Late in the 19th century various governments acted to redefine their base standards on a scientific basis and establish ratio-metric equations to SI metric system standards. They did not always pick the same equivalencies, though the pound remained very similar; these independent legal actions led to small differences in certain quantities, such as the American and Imperial pounds.An alternative system of mass, the troy system, is generally used for precious materials. The modern definition of the avoirdupois pound (1 lb) is exactly 0.45359237 kilograms.

Candy (unit)

The candy or candee (Marathi: खंडी, khaṇḍī; Tamil: கண்டி, kṇṭi; Malayalam: kaṇḍi, kaṇṭi), also known as the maunee, was a traditional South Asian unit of mass, equal to 20 maunds and roughly equivalent to 500 pounds avoirdupois (227 kilograms). It was most used in southern India, to the south of Akbar's empire, but has been recorded elsewhere in South Asia. In Marathi, the same word was also used for a unit of area of 120 bighas (25 hectares, very approximately), and it is also recorded as a unit of dry volume.

The candy was generally one of the largest (if not the largest) unit in a given system of measurement. The name is thought to be derived from the Sanskrit खण्डन (root खुड्) khaṇḍ, "to divide, break into pieces", which has also been suggested as the root of the term (sugar-)candy. The word was adopted into several South Asian languages before the compilation of dictionaries, presumably through trade as several Dravidian languages have local synonyms: for example ఖండి kaṇḍi and పుట్టి puṭṭi in Telugu.

Coin grading

Coin grading is the process of determining the grade or condition of a coin, one of the key factors in determining its value. A coin's grade is generally determined by five criteria: strike, preservation, luster, color, and attractiveness. Several grading systems have been developed. Certification services professionally grade coins for tiered fees.

English units

English units are the units of measurement that were used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at different times, in different places, and for different applications.

The two main sets of English units were the Winchester Units, in effect from 1495–1587, as reaffirmed by King Henry VII, and the Exchequer Standards, in effect from 1588–1825, as first defined by Queen Elizabeth I.The units were replaced by Imperial Units in 1824 (effective 1 January 1826) by a Weights and Measures Act, which retained many but not all of the unit names and redefined many of the definitions.

Use of the term "English units" can be ambiguous, as in addition to the meaning used in this article, it is sometimes mistakenly used to refer to either: United States customary units, which have somewhat different definitions; or to Imperial units, the previous standard units throughout the British Empire and the Commonwealth.

Exchequer Standards

The Exchequer Standards may refer to the set of official English standards for weights and measures created by Queen Elizabeth I (English units), and in effect from 1588 to 1826, when the Imperial Units system took effect, or to the whole range of English unit standards maintained by the Court of the Exchequer from the 1200s, or to the physical reference standards physically kept at the Exchequer and used as the legal reference until the such responsibility was transferred in the 1860s, after the Imperial system had been established.The Exchequer standards made in the reign of Queen Elizabeth were not authorized by any statute. The standards were ordered by the royal authority, as appears from a roll of Michaelas terms in the 29th Elizabeth, preserved in the Queen's Remembrancer's Office, and containing the royal proclamation.The Exchequer Standards were so called because their repository had always been the Court of the King's Exchequer.Notably, Elizabeth I's redefinition of these standards instituted the English Doubling System, whereby each larger liquid measure equals exactly two of the next-smaller measure.


Gold is a chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native) form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum) and also naturally alloyed with copper and palladium. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides).

Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of nitric acid and hydrochloric acid, which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in metallic objects, giving rise to the term acid test. Gold also dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction.

A relatively rare element, gold is a precious metal that has been used for coinage, jewelry, and other arts throughout recorded history. In the past, a gold standard was often implemented as a monetary policy, but gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard was abandoned for a fiat currency system after 1971.

A total of 186,700 tonnes of gold exists above ground, as of 2015. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold's high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices (its chief industrial use). Gold is also used in infrared shielding, colored-glass production, gold leafing, and tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine. As of 2017, the world's largest gold producer by far was China with 440 tonnes per year.

Gold coin

A gold coin is a coin that is made mostly or entirely of gold. Most gold coins minted since 1800 are 90–92% gold (22 karat), while most of today's gold bullion coins are pure gold, such as the Britannia, Canadian Maple Leaf, and American Buffalo. Alloyed gold coins, like the American Gold Eagle and South African Krugerrand, are typically 91.7% gold by weight, with the remainder being silver and copper.

Traditionally (up to about the 1930s), gold coins have been circulation coins, including coin-like bracteates and dinars. Since recent decades, however, gold coins are mainly produced as bullion coins to investors and as commemorative coins to collectors. While modern gold coins are also legal tender, they are not observed in everyday financial transactions, as the metal value normally exceeds the nominal value. For example, the American Gold Eagle, given a denomination of 50 USD, has a metal value of more than $1,300 USD.

The gold reserves of central banks are dominated by gold bars, but gold coins may occasionally contribute.

Gold has been used as money for many reasons. It is fungible, with a low spread between the prices to buy and sell. Gold is also easily transportable, as it has a high value to weight ratio, compared to other commodities, such as silver. Gold can be re-coined, divided into smaller units, or re-melted into larger units such as gold bars, without destroying its metal value. The density of gold is higher than most other metals, making it difficult to pass counterfeits. Additionally, gold is extremely unreactive, hence it does not tarnish or corrode over time.

Grain (unit)

A grain is a unit of measurement of mass, and in the troy weight, avoirdupois, and Apothecaries' system, equal to exactly 64.79891 milligrams. It is nominally based upon the mass of a single virtual ideal seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definitions of units of mass. Rather, expressions such as "thirty-two grains of wheat, taken from the middle of the ear" appear to have been ritualistic formulas, essentially the premodern equivalent of legal boilerplate. Another source states that it was defined as the weight needed for 252.458 units to balance a cubic inch of distilled water at 30 inches of mercury pressure and 62 degrees Fahrenheit for both the air and water. Another book states that Captain Henry Kater, of the British Standards Commission, arrived at this value experimentally.The grain was the legal foundation of traditional English weight systems, and is the only unit that is equal throughout the troy, avoirdupois, and apothecaries' systems of mass. The unit was based on the weight of a single grain of barley, considered equivalent to ​1 1⁄3 grains of wheat. The fundamental unit of the pre-1527 English weight system known as Tower weights, was a different sort of grain known as the "wheat grain". The Tower wheat grain was defined as exactly ​45⁄64 of a troy grain.Since the implementation of the international yard and pound agreement of 1 July 1959, the grain or troy grain (symbol: gr) measure has been defined in terms of units of mass in the International System of Units as precisely 64.79891 milligrams. 1 gram is approximately 15.43236 grains. The unit formerly used by jewellers to measure pearls, diamonds, and other precious stones, called the jeweller's grain or pearl grain, is equal to ​1⁄4 of a carat, or 50 mg (~ 0.7716 gr). The grain was also the name of a traditional French unit equal to 53.115 mg.In both British Imperial and U.S. customary units, there are precisely 7,000 grains per avoirdupois pound, and 5,760 grains per troy pound or apothecaries pound.

Hong Kong units of measurement

Hong Kong has three main systems of units of measurement in current use:

The Chinese units of measurement of the Qing Empire (no longer in widespread use in mainland China);

British Imperial units; and

The metric system.In 1976 the Hong Kong Government started the conversion to the metric system, and as of 2012 measurements for government purposes, such as road signs, are almost always in metric units. However, all three systems are officially permitted for trade, and in the wider society a mixture of all three systems prevails.

Imperial units

The system of imperial units or the imperial system (also known as British Imperial or Exchequer Standards of 1825) is the system of units first defined in the British Weights and Measures Act of 1824, which was later refined and reduced. The Imperial units replaced the Winchester Standards, which were in effect from 1588 to 1825. The system came into official use across the British Empire. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement, although some imperial units are still used in the United Kingdom, Canada and other countries formerly part of the British Empire. The imperial system developed from what were first known as English units, as did the related system of United States customary units.


Osmium (from Greek ὀσμή osme, "smell") is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with an experimentally measured (using x-ray crystallography) density of 22.59 g/cm3. Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen nib tipping, electrical contacts, and in other applications that require extreme durability and hardness. The element's abundance in the Earth's crust is among the rarest.

Pound (mass)

The pound or pound-mass is a unit of mass

used in the imperial, United States customary and other systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbm (for most pound definitions), # (chiefly in the U.S.), and ℔ or ″̶ (specifically for the apothecaries' pound).

The unit is descended from the Roman libra (hence the abbreviation "lb"). The English word pound is cognate with, among others, German Pfund, Dutch pond, and Swedish pund. All ultimately derive from a borrowing into Proto-Germanic of the Latin expression lībra pondō ("a pound by weight"), in which the word pondō is the ablative case of the Latin noun pondus ("weight").Usage of the unqualified term pound reflects the historical conflation of mass and weight. This accounts for the modern distinguishing terms pound-mass and pound-force.

Precious metal

A precious metal is a rare, naturally occurring metallic chemical element of high economic value.

Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial commodities. Gold, silver, platinum, and palladium each have an ISO 4217 currency code.

The best known precious metals are the coinage metals, which are gold and silver. Although both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded.

The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded much higher prices than common industrial metals.

System of measurement

A system of measurement is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce. Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the imperial system, and United States customary units.


Troyes (French pronunciation: ​[tʁwa]) is a commune and the capital of the department of Aube in the Grand Est region of north-central France. It is located on the Seine river about 150 km (93 mi) southeast of Paris. Troyes is situated within the Champagne wine region and is near to the Orient Forest Regional Natural Park. Many half-timbered houses (mainly of the 16th century) survive in the old town. Troyes has been in existence since the Roman era, as Augustobona Tricassium, which stood at the hub of numerous highways, primarily the Via Agrippa.

United States customary units

United States customary units are a system of measurements commonly used in the United States. The United States customary system (USCS or USC) developed from English units which were in use in the British Empire before the U.S. became an independent country. However, the United Kingdom's system of measures was overhauled in 1824 to create the imperial system, changing the definitions of some units. Therefore, while many U.S. units are essentially similar to their Imperial counterparts, there are significant differences between the systems.

The majority of U.S. customary units were redefined in terms of the meter and the kilogram with the Mendenhall Order of 1893 and, in practice, for many years before. These definitions were refined by the international yard and pound agreement of 1959.Americans primarily use customary units in commercial activities, as well as for personal and social use. In science, medicine, many sectors of industry, and some of government and military, metric units are used. The International System of Units (SI), the modern form of the metric system, is preferred for many uses by the U.S. National Institute of Standards and Technology (NIST). For newer units of measure where there is no traditional customary unit, international units are used, sometimes mixed with customary units, such as electrical resistance of wire expressed in ohms (SI) per thousand feet.

Winchester measure

Winchester measure is a set of legal standards of volume instituted in the late 15th century (1495) by King Henry VII of England and in use, with some modifications, until the present day. It consists of the Winchester bushel and its dependent quantities, the peck, (dry) gallon and (dry) quart. They would later become known as the Winchester Standards, named because the examples were kept in the city of Winchester.

Winchester measure may also refer to:

the systems of weights and measures used in the Kingdom of Wessex during the Anglo-Saxon period, later adopted as the national standards of England, as well as the physical standards (prototypes) associated with these systems of units

a set of avoirdupois weight standards dating to the mid-14th century, in particular, the 56-pound standard commissioned by King Edward III, which served as the prototype for Queen Elizabeth I's reform of the avoirdupois weight system in 1588

a type of glass bottle, usually amber, used in the drug and chemical industry, known variously as the Boston round, Winchester bottle, or Winchester quart bottle

Zechariah 5

Zechariah 5 is the fifth chapter of the Book of Zechariah in the Hebrew Bible or the Old Testament of the Christian Bible. This book contains the prophecies spoken by the prophet Zechariah, and is a part of the Book of the Twelve Minor Prophets.

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