The Cook Islands, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar circulates in parallel with the local Cook Islands Dollar; at the same time, the government also authorises many legal tender coins in the Cook Islands Dollar currency for collector's purposes.
Collector coins are dedicated to historical or general popular culture themes not related to the country itself. Many of them are in bullion sizes based on the troy ounce, but some are "metric", like twenty-five grams (25g) of silver. | 
