1979 Canadian half dollars come into varieties: one with the Queens bust rounded at the top, and the less common depiction with a pointed bust. Their value can reach $2.00 and $4.50, respectively. This, of course, depends on quality.
A US half dollar with a date of 1979 is a Kennedy half dollar not a liberty half dollar. The coin has no silver and is only face value.
A 1964 Canadian half-dollar has a value of approximately $12 Canadian dollars. This value is dependent on the current silver market.
50 cents
With the date of 1979 the coin is a Kennedy half dollar, it's worth 50 cents.
The U.S. half dollar has never been made of gold. What you probably have is a gold-plated 1979 half-dollar. It's not really worth much above face value.
5 bucks
Unless it's in brand-new uncirculated condition, face value only.
Please post a new question with the coin's date.
The value of an 1896 Canadian half dollar depends on its condition. For example, such a coin in good condition is worth around 11.79 US dollars while an uncirculated coin has a value of more than 500 US dollars.
There is no silver in the Canadian half dollar dated after 1967. If you have older coins (lucky you), the content is as follows: 1870 - 1919 92.5% silver 7.5% copper 1920 - 1967 80% silver 20% copper
for a non-collector it would be 50 cents
With a date of 1979 the coin has no silver in it. 1969 was the last 40% silver circulating US half dollar. The coin is worth 50 cents.