Panama is kinda famous for large silver coins. Between 1971 and 1985 they went all-out with their giant 20 balboas. These coins measure 61 mm in diameter (a US silver dollar measures 38 mm) and weigh over 100 grams each.
For the most part, these coins are worth their weight in silver. There is substantial silver in these coins, and we list those figures below. The Panamanian government purposely limited the production of a few dates (I don't like that, by the way) and these dates are more valuable than silver content alone.
Also, these coins come with fancy packaging and Certificates of Authenticity. These are worth zero (another thing I don't like!).
Here are the silver weights. To find the current value, multiply the price of silver by the weight. So, for instance, if silver is $30 US dollars per troy ounce (look it up on web sites such as kitco.com), a 1971 20 balboas with 3.854 troy ounces of silver would be worth 30 x 3.854 = $115 US dollars.
COINS DATED 1971 TO 1979: 3.854 troy ounces silver
COINS DATED 1980 TO 1985: 1.927 troy ounces silver
Coins with the following dates and mint marks have artificially limited mintage and their prices may be higher.