2013 Two Coin Uncirculated Year Set-Australian Mining, featuring the 'Discovery of Gold' One Dollar Coin and the 'Australian Mining' Twenty Cent Coin, Mintage: No more than 40,000. Weight: $1: 9.0 gr, 20c: 11.3 gr, Diameter: $1: 25.0 mm, 20c: 28.52 mm Please contact Adelaide Exchange Jewellers to find out more on this item.