Jamaica issued these coins in many sizes and many metals. The first year of issue, 1971, uses a different portrait of Norman Manley. Of all the issues, only a few are made of silver and are therefore valuable above face value. The others are worth face value. A collector might be willing to pay a few US dollars for a superb non-silver specimen.
This page shows only those coins made of silver. To compute value, look up the current price of silver (at, for instance, www.kitco.com) and multiply by the silver weight shown below.
1971, first portrait, 45 mm diameter, 1.25 troy ounces silver
1972 and 1973, second portrait, 45 mm diameter, 1.23 troy ounces silver
1974 to 1979, only 42 mm diameter, 0.604 troy ounces silver
1980 to 1984, only 36 mm diameter, 0.298 troy ounces silver
1983 and 1993, only the proof coins, 0.298 troy ounces silver