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 rising price of silver spelled doom for its use in circulating coinage after the mid 1960s. The dimes and quarters dated 1967 were produced in both the normal .800 fine silver and in a reduced .500 silver. The latter continued into 1968 for these two coins, but a non-silver composition was phased in that year. The production of silver halves ended abruptly with the centenary issue of 1967, and later pieces were of nickel. Thus ended Canadaâs rich history of circulating silver coins.