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 last year silver dollars were minted for circulation was 1935. However, the last year any traditional silver dollars were made is 1964. Under pressure from the silver lo â¦ bby and the gaming industry and with the support of President Johnson, the Mint made a trial run of about 310,000 Peace dollars in 1964.