Dogbrain said:
While we only have one "copper coin" we have multiple "silver" coins. Thus, IT IS NOT THE SAME WITH US COINS. We DO have a "silver" coin worth 1/10 the value of another "silver coin".
If you go by actual physical composition, it's
penny : Copper plated zinc. 2.5% copper, 97.5% zinc. weight: 2.500 g
nickel : Cupro-nickel. 25% nickel, 75% copper. weight: 5.000 g
dime : Cupro-nickel. 8.33% nickel, 91.66% copper. weight: 2.268 g
quarter : Cupro-nickel. 8.33% nickel, 91.66% copper. weight: 5.670 g
half-dollar : Cupro-nickel. 8.33% nickel, 91.66% copper. weight: 11.340 g
Susan B. Anthony "silver" dollar : Cupro-Nickel. 12.5% nickel, 87.5% copper. weight: 8.1 g
Sacagawea "golden" dollar: Manganese-Brass. 88.5% copper, 6% zinc, 3.5% manganese, 2% nickel. weight: 8.1 g
(source:
U. S. Mint)
So, we have one (mostly-)zinc denomination and 5 (mostly-)copper denominations.
However, before 1965, most dimes, quarters, and half-dollars were 90% silver, 10% copper. A small portion of Eisenhower dollars minted between 1971 and 1978 contained roughly 40% silver, as did a small portion of the bicentennial quarters and half-dollars minted in 1975 and 1976. The rest were the same makeup as the Susan B. Anthony dollars.
(Source:
A Guide Book of United States Coins. 48th Edition 1995. By R. S. Yeoman. (C) 1994 Western Publishing Co.; Racine, WI.)