1 Crown - Elizabeth II Sapphire Jubilee, Gold

Tristan da Cunha, a British Overseas Territory in the South Atlantic with a permanent population under 300, issues commemorative coins primarily for the collector market — none of this type entered general circulation on the island. The "Gold" designation here requires careful reading: the core is 9-carat (.375) gold, plated in .9999 fine gold, bringing the actual fine gold content of a 1-gram piece to a fraction of a fraction of a gram.

The Sapphire Jubilee marked Elizabeth II's 65th year on the throne in 2017, the first British monarch to reach that milestone.