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.
This coin dedicated to the 400th Anniversary of detailed observation of Mars is part of the Meteorite Impacts collection which is issued in a number of different countries; all coins in it have an embedded original piece of a specific meteorite.
The mint says about this coin:
Mars is an earth-like planet in our solar system. With a diameter of approximately 6,800 kilometres it is about half the size of the Earth. A high percentage of iron oxide (rust) is responsible for its reddish shimmer. Due to this (blood red) colour it was granted the Roman God of Wars name. Through its brightness it was already known in ancient days.
The planet Mars was observed more precisely for the first time with Galileo Galilei’s telescope. Up until today the fascination of this orb is unbowed. For the first time ever Mars meteorite stone has been inserted in this coin edition. This stone belongs to the scarcest possessions a private persons can have. There are less than 100 kilograms of it worldwide. How is a specification of the meteorite possible at all? The earth probes on Mars, Voyager, Rover or Phoenix, have examined the Martian soil intensively. This geological data served as a basis for the allocation of its origin by which the meteorites were defined. Therefore it could precisely be determined that this meteorite NWA 4925 of the type olivine-phyric shergottite originates from Mars. | 
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