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.
Any United States dime, quarter, half dollar or dollar that is dated 1964 or earlier is made of 90% silver. In the dime series, all coins dated 1965 or later are clad coins and contain no silver at all. The value of these coins is tied directly to the price of silver. At $20 per ounce, 90% silver coins are worth about fourteen times their face value. A dime would be worth about $1.40, a quarter about $3.50, and a half dollar, about $6.00. At the same silver price of $20, 40% silver half dollars are worth approximately $2.50 each.