1 Koula - Salote Tupou III

Tonga's 1962 platinum koula is one of the earliest platinum circulation-intended issues from any Pacific nation, produced during the reign of Queen Salote Tupou III, who ruled for 47 years and remains one of the most consequential monarchs in Tongan history — widely remembered internationally for her open-carriage appearance in the rain at Elizabeth II's 1953 coronation. The .999 platinum composition places this well outside routine coinage practice for the period; platinum issues in 1962 were effectively unknown outside of specialized bullion contexts.

The KM#3a / Schön#3b designation distinguishes this from the gold-composition sibling, KM#3.