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.
Silver dimes and quarters were minted from 1796 to 1964. Most of them were made of 90% silver and 10% copper. For other denominations, halves were silver from 1794 to 1970, bâ¦ut those dated 1965-1970 were made of 40% silver, not 90% silver. Silver dollars were made of 90% silver up till 1935.