The U.S. didn't issue any $1 coins in 1958, and no circulating gold coins have been minted since 1933. Please post a new question with more details including a description of the coin and its country...
There were 8 million of these 1 Dinar coins featuring King Peter I (1903-18) minted that year. It contains .1342 of an ounce of silver and it may currently be worth about $3 with heavy wear to around...
Assuming you mean a American Silver Eagle dated 1987 the value is the same as the spot price of silver at the time of sale, but right now it's $19.23, that's the spot price as type this answer.