1837 was the year US silver coins changed to .900 silver & .100 copper, that caused a slight reduction of silver.
Coins struck for circulation in the US today have no silver in them.
ZERO, because no dollar US coins were made dated 1970
U.S. dimes, quarters, half dollars, and silver dollars dated 1964 or earlier contain 90% silver with 10% copper.
.773 Oz of silver in all Morgan and Peace dollars. A good place to check the melt value of US coins is http://www.coinflation.com/
Generally 90% silver, 10% copper. There were minor adjustments in the 19th century but anything you find from the 1870s forward will be so-called "coin silver".
Coins struck for circulation in the US today have no silver in them.
ZERO, because no dollar US coins were made dated 1970
Inflation caused the silver content of coins to be worth more than their face value so the US mint stopped making silver coins for circulation.
All US silver coins before 1964 were 90% silver. Peace dollars weigh 26.7 gm if not worn, so they contain about 24 gm of pure silver.
U.S. dimes, quarters, half dollars, and silver dollars dated 1964 or earlier contain 90% silver with 10% copper.
No coin is 100% pure silver as 100% silver does not exist, the refining proces does not produce 100% metals. The easiest way to determine silver content is to look up the coin in an appropriate numismatic reference source. which will display metal content and weight for the specific coin you are referencing along with many other details. US collectible and bullion coins are 99.9% pure US circulating coins used to have silver content ranging from 85-97.5% but now are mostly copper with silver cladding.
No British coin has ever been 100% silver. For hundreds of years, British silver coins had a very high proportion of silver in them. From the Great Recoinage Act of 1816, British silver coins were standardised to sterling silver with a 92.5% silver content. The use of sterling silver to mint silver coins continued until 1919/1920 when, due to a sharp increase in the price of silver, British coins were debased to 50% silver. The 50% silver content continued to 1946 when, due to Britains pressing need to repay war loans to the US, the use of silver was discontinued. All British silver coins from 1947 onwards were made from a copper-nickel alloy.
.773 Oz of silver in all Morgan and Peace dollars. A good place to check the melt value of US coins is http://www.coinflation.com/
At the present time, the US has silver colored coins made out of nickel, alloys of copper and nickel, and other metals, but it no longer uses actual silver, which is very expensive. Historically, when coins were first introduced in earlier civilizations, and even in the earlier years of US history, the value of a coin was the value of the metal of which it was made. Silver coins were valuable because they were made of silver, a precious metal, gold coins were even more valuable, and copper coins were less valuable because copper is a less expensive metal, although still expensive enough that coins made out of copper have value because of their metal content. Now the value of US coins is like the value of US paper currency, something that the government declares, rather than being the result of valuable metal content. But out of tradition, the higher denominations are still silver at least in color, and pennies are still copper.
The only coins dated 1967 to have any silver are the Kennedy halves. From 1965 to 1970 they are 40% silver, 1964 and earlier halves, quarters and dimes are all 90% silver.
First off, they are not sterling silver, sterling silver is 92.5% pure silver, most silver US coins are 90% silver and 10% copper, known occasionally as "coin silver". In average circulated condition, the coin is only worth its silver content, at the time of writing, it is about $5.50 in silver content. If it is in mint-state or otherwise very good condition, it might be worth more than just its silver content if you can find a collector.
Generally 90% silver, 10% copper. There were minor adjustments in the 19th century but anything you find from the 1870s forward will be so-called "coin silver".