50 Pence - Elizabeth II Platinum Wedding - The Royal Engagement, Gold Proof

The 2017 platinum wedding commemoration — marking 70 years of marriage between Elizabeth II and Prince Philip — prompted a wave of Isle of Man issues, the territory having built its reputation as a prolific producer of royal commemoratives since the 1970s. The Isle of Man's treasury has long operated with unusual latitude in issuing commemorative coinage, unbound by the stricter controls governing Royal Mint output, which explains both the volume and the variety of formats released for this occasion.

The .916 gold specification places this in the traditional 22-carat crown gold standard, the same fineness used for British sovereigns since 1817.