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.
U.S. Circulated Silver Coins. Silver coin values below are based on live silver prices at the CME. These coins were in standard circulation until silver was removed from all coinage in 1965 and 1970 (40% silver half-dollars). The values below only reflect the silver value, not rarity or numismatic value.