We went to the Cook Islands on our way to Australia in 1988.

The Cook Islands $2 coin is a distinctive, triangular-shaped coin featuring Queen Elizabeth II on the obverse and a "Kumete" (traditional mortar and pestle) on the reverse. Introduced in 1987, the currency is pegged at par with the New Zealand dollar.

It has a depiction of a "Kumete" which has been traditionally used to pound root foods such as arrowroot. This particular "Kumete" is a traditional one from the island of Atiu and is illustrated in Sir Peter Bucks great work on Polynesian artifacts.
en.numista.com/4436

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