Are US coins prior to 1965 90% silver by mass or volume?

Question

Coins > $0.05 in face value minted in the USA prior to 1965 are 90% silver. But no one has ever explained to me whether that's 90% by weight, or by volume. Because copper (the other 10%) and silver have different densities, the answer to my question is a small, but nontrivial difference, expecially if considering a large coin hoard. Most of the conversion calculations I've seen on the internet seem to favor the 90% by mass (weight) but I've never seen a definitive answer.

Answer 1

Lets start from the beginning here, nickels as we call them are are .750 copper and .250 nickel. The nickels to have silver in them are some of the 1942 and all 1943-1945, they are .560 copper, .350 silver and .090 manganese. the net weight of silver is .05626 oz of pure silver. Volume is used to measure liquids. From about 1837 to and including 1964 the coinage made of silver was .900 silver and .100 copper. That made the coin 90% silver. Of course the larger the coin the more silver in weight was in it. By the way precious metals are weighed using the troy ounce system of 12 ounces to the pound. See a dictonary for for Troy weight. The coins with silver, the dime .07234 oz, quarter .18084 oz.,1/2 dollar .36169 oz., 1965-1970 silver clad 1/2 dollars .14792 oz and Morgan and Pease dollars .77344 oz. These amounts are the actually silver weight. the silver Ike clad dollars have .3161 oz of actual silver weight. Hope this answers your question.