The 2004 loonie is notable primarily for what changed that year rather than what was produced: the Royal Canadian Mint quietly altered the plating process on the aureate-bronze finish to improve adhesion and reduce delamination complaints that had accumulated through the late 1990s production runs. Most collectors cannot distinguish the pre- and post-change pieces without laboratory analysis, but the KM#507 designation tracks the revised specification.
The 2004 loonie is notable primarily for what changed that year rather than what was produced: the Royal Canadian Mint quietly altered the plating process on the aureate-bronze finish to improve adhesion and reduce delamination complaints that had accumulated through the late 1990s production runs. Most collectors cannot distinguish the pre- and post-change pieces without laboratory analysis, but the KM#507 designation tracks the revised specification.