The gestation period for an elephant is 640 to 660 days. This is equivalent to about 95 weeks, or 22 months, and is the longest gestation period of any mammal.
Dimes dated after 1964 are copper-nickel clad and contain no silver. Quarters are also clad, except for the bicentennial commemorative coins with an S mint mark that were produced for mint and proof sets. Kennedy half dollars from 1965 to 1970 were 40 percent silver composition. After 1970, all Kennedy halves were clad, except the same S bicentennial issue.
Most of the melting took place in 1979 and 1980, when silver bullion soared to an all-time high of $50 an ounce. At that point, common-date silver coins were worth far more as metal than as money or collectibles. Even scarcer items could be melted at a profit. The value of silver has plummeted since then.