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Bronze disease is the chloride corrosion of cuprous (copper-based) artifacts. It was originally thought to be caused by bacteria. [ 1 ] It is contagious in that the chlorides which cause it can spread the condition if they are brought into contact with another cuprous object. Despite its name, bronze disease can affect any copper-bearing alloy ...
Rome, Florence, and Venice followed with coins of denominations greater than a penny, and late in the 12th century Venice minted a silver coin equal to 24 pennies. By the mid-13th century Florence and Genoa were minting gold coins, effectively ending the reign of the silver penny ( denier , denarius ) as the only circulating coin in Europe.
Design date. 2009–present. The Sacagawea dollar (also known as the " golden dollar ") is a United States dollar coin introduced in 2000, but subsequently minted only for niche circulation from 2002 onward. The coin generally failed to meet consumer and business demands. It is still generally accepted in circulation.
By 1160 bronze coins had become a rarity, and became largely an abstract measurement of value rather than a tangible currency, the most important attribute of bronze coins after this year was as a measurement for the value of other currencies, by 1161 a shortage in wén coins had forced the Southern Song government to halve the salary of their ...
The Susan B. Anthony dollar is a United States dollar coin minted from 1979 to 1981, when production was suspended due to poor public acceptance, and then again in 1999. . Intended as a replacement for the larger Eisenhower dollar, the new smaller one-dollar coin went through testing of several shapes and compositions, but all were opposed by the vending machine industry, a powerful lobby ...
Gold, silver and bronze or copper were the principal coinage metals of the ancient world, the medieval period and into the late modern period when the diversity of coinage metals increased. Coins are often made from more than one metal, either using alloys, coatings (cladding / plating) or bimetallic configurations.
This hoard, weighing over 1,300 pounds and containing more than 50,000 bronze coins from the late third and early fourth centuries AD, was concealed with bricks and ceramic filler.
Ptolemaic coinage. A silver tetradrachm of Ptolemy IV Philopator (r. 221 – 205 BC); an undated issue from the Arados royal mint, struck c. 214–212 BC, 26 mm in width, 14.10 gm in weight; the obverse shows a diademed head of Ptolemy I Soter wearing the aegis, while the reverse shows an eagle standing on a thunderbolt with a Greek inscription ...