With spot silver @ $24.68 per oz. + $1.00 over = $25.68 divided by 31.1035 grams per oz. = .83 cents per gram x 20 grams = $16.60 pure silver value. Add a few dollars for age and condition and it would probably be worth about $20.00. A lot depends on condition of the coin!
Most of the coins are worth about $20 each. The exact price of these coins will depend upon its condition.
"Una Onza Troy de Plata Pura" is Spanish for "One Troy Ounce of Pure Silver". I think that you're asking about the Mexican "Onza" coin, although it has only been issued since 1982, which contains 1 troy ounce of silver and trades at its bullion value (although some dates trade at a small premium if they are in Brilliant Uncirculated or Proof condition).
The value of a 1928 Mexican centavos coin depends on the denomination and condition of the coin. The typical value is between 6 and 65 US dollars.
centavos 1954 coin
no such coin
The coin is still only face value.
The coin is face value.
1967 centavos coin worth
what is value of a south African 1978 fine gold Krugerrand coin
what is the value of a Jackie Robinson legacy coin set with baseball cqard and gold coin
$2125.00
The coin is still in circulation today and has face value only.
$60-80