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.
The US Dime and Quarter Dollar changed from 90% silver to 0% silver after 1964. The US Half Dollar went from 90% silver to 40% silver from 1965 through 1970 after that it contained 0% silver. The US Dollar had 90% silver until they stopped making them in 1935.