20 Dollars - Charles III Moon phases

The Moon Phases series from the Royal Canadian Mint uses selective black rhodium plating to create the darkened sky effect — a technique the RCM has refined over roughly a decade of applying rhodium to silver blanks before striking. The KM# range spanning 3593–3599 indicates seven distinct issues within the series, each capturing a different lunar phase.

Black rhodium on .9999 fine silver is technically demanding: rhodium adhesion at that purity requires precise surface preparation, and the plating boundary where the moon emerges from the darkened field is the most failure-prone point in production.