What is the value of a miniature 50 cent coin?

Answer 1

If it's a miniature coin it's a privately-issued piece and not one of the "American Eagle" coins struck by the US Mint. Its value would depend on its gold content.

If the content and fineness are on the back of the coin, multiply the weight by the fineness and multiply that result by the current price of gold (see, e.g., a site like kitco.com). That will give you its retail value; assume about half that amount for what a metal dealer will pay.

If the content and fineness are NOT on the back of the coin, it's probably just plated and doesn't have enough gold to be worth very much.

Answer 2

It depends, such a coin was not made by the US mint, so no serious coin collectors would want to buy it, however, such a coin could be struck in silver in which case it would be worth the value of the silver. However, if the coin was struck in lead, brass, nickel, copper, etc. it isn't worth hardly anything. The coin itself is worthless, any value would come from the metals used to make the coin.