Niue, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar is the circulation currency for daily transactions, while the government also authorises legal tender coins in the Niue Dollar currency for collector's purposes.
A number of mints issue a large variety of commemorative and collector coins under the authority of Niue. These coins are dedicated to historical or general popular culture themes not related to Niue itself. Many of them are in bullion sizes based on the troy ounce - such as a fifth-ounce of gold (abbreviated as 1/5 oz Au, where "Au" comes from the Latin word for gold, Aurum), or similar.
The coins are "Non-Circulating Legal Tender" (NCLT) and not bullion because they are issued at prices much higher than their bullion value and are targeted at collectors who appreciate them for their artistic or sentimental value, and not at bullion investors. | 
