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. Many of them are in standard sizes, including the half gram (0.5 g) of gold mini-coin format - such as this coin.
The Mint says about this coin:
Following on the heels of the immensely successful "The Number of the Beast" Iron Maiden coin, CIT is thrilled to release the next heavy metal hit! There are three incredible issues that are all designed around the band’s newest album release, "Senjutsu". It is a global success having hit #1 in 23 countries.
The name is Japanese and loosely translates to "tactics and strategy". It is unlike any other album that Iron Maiden has done before and the band continues to sound like no other. Iron Maiden is well known for fancy album artwork revolving around Eddie and this album is no exception. Eddie is shown donning ancient Samurai style armour and wielding a Samurai sword. CIT has taken this officially licensed design and mated it to our impressive smartminting technology.
The 2 oz silver proof is a stunning blending of our state-of-the-art coloration and ultra-high relief. The colourful 5 gram silver note is also a sight to behold and uses every bit of its surface to showcase this striking design. The half gram gold proof is astonishingly detailed for its size and makes a great compliment to the other two releases. With their Legacy of the Beast tour going around the world this year, these will surely be in high demand. | 
Search for Cook Islands: Gold Half Gram 2022 Iron Maiden - Senjutsu on eBay 