New Zealand uses the New Zealand Dollar as its circulation currency for daily transactions. The country also issues a number of commemorative and collector coins, including in the internationally popular one ounce of silver format (abbreviated as 1 oz Ag, where "Ag" comes from the Latin word for silver, Argentum). Authorised by the Reserve Bank of New Zealand, the official issuer of these coins is NZ Post - which also issues the country's postal stamps. Manufacturing of the coins is commissioned to various foreign mints.
The coins are "Non-Circulating Legal Tender" (NCLT) and not bullion because they are issued at prices much higher than their intrinsic value and are targeted at collectors who appreciate them for their artistic or sentimental value, and not at bullion investors.
This coin is part of a range featuring Māori legends.
NZ Post says about ot:
Ranginui (the sky father) and Papatūānuku (the earth mother), the primordial parents, held each other in a tight embrace and bore many sons. Tāne - the god of the forest - separated his parents, creating the world of light. Rangi and Papa were heartbroken when they parted. The older brothers were infuriated by the endless rain and sadness, and decided to turn their mother away from her love. Rūaumoko (Ruaumoko) was at his mother’s breast, so he was carried to the underworld. Rūaumoko still moves under the earth, creating earthquakes and volcanoes. | 
Search for New Zealand: Silver Ounce 2023 Rūaumoko - Guardian of Volcanoes on eBay 