A mule coin occurs when a mint accidentally uses mismatched dies, striking one coin’s obverse or reverse with the design meant for a different coin. Here are a few of my recent acquisitions. These 2 being the first of their kind in my collection. Provident Prospector 1 oz Silver Round V1 – Error Copper Mule This silver round was mistakenly minted with the reverse of the copper version of the same coin. While it retains its original obverse design, collectors can clearly see the errant “copper” marking on the reverse side. 2016 Provident Year of The Monkey 1 oz Silver Round – Error Copper Mule Post any Mule Coins