Here is four square coins from Nederlandse Antillen, from 1963 to 1967. These very uniquely shaped coins are fairly rare with not a lot minted. They are made of Copper and Nickel, weigh 4.5 grams and are 21.3 mm in diameter. The coins are:
Coin Mintage
1 X 1963 400,000
1 X 1965 500,000
2 X 1967 600,000
