RARE VINTAGE LOT 8K Solid Gold COIN. 4 miniature Gold coins IN TOTAL!! 2 – Pope John XXIII. 1 – Pope John Paul I. 1 – Pope John Paul II. Miniature Gold coins. Note : STUNNING LOT gold coins Collection Pope. The world’s smallest gold 8K coins. The measures of each Gold 8k coin : 1,1 cm (diameter) with a weigh from approximately 9/10 of a gr to 1.0 gr!! Belonging to my private collection.