Nickel (United States coin)
A nickel is a five-cent coin struck by the United States Mint. Composed of cupronickel, the piece has been issued since 1866. Its diameter is 0.835 inches (21.21 mm) and its thickness is 0.077 inches (1.95 mm).
Nickel (United States coin)
A 1796 half dime
Spencer M. Clark, Supervisor of the Currency Bureau, placed his own likeness on the five-cent U.S. Fractional currency note, leading directly to legislation prohibiting the depiction of any living person on U.S. currency.
NNC-US-1866-5C-Shield Nickel (rays)
A coin is a small object, usually round and flat, used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to facilitate trade. They are most often issued by a government. Coins often have images, numerals, or text on them. The faces of coins or medals are sometimes called the obverse and the reverse, referring to the front and back sides, respectively. The obverse of a coin is commonly called heads, because it often depicts the head of a prominent person, and the reverse is known as tails.
A selection of metal coins
An oxhide ingot from Crete. Late Bronze Age metal ingots were given standard shapes, such as the shape of an "ox-hide", suggesting that they represented standardized values.
Coin of Alyattes of Lydia, c. 620/10–564/53 BC
The earliest inscribed coinage: electrum coin of Phanes from Ephesus, 625–600 BC. Obverse: Stag grazing right, ΦΑΝΕΩΣ (retrograde). Reverse: Two incuse punches, each with raised intersecting lines.