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.
Best Answer: The US minted 90% silver dimes, quarters, and half dollars for circulation through 1964. After that, dimes and quarters were minted for circulation in copper-nickel. From 1965 to 1969, half dollars were silver-clad and contained 40% silver.