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, bullion 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 made using "smartminting" techniques and have features not generally found in circulation coins - e.g. high relief, full colour printing and/or different forms, including fully three dimensional (3D).
Some coins are marketed in standard bullion sizes, like half ounce silver, one ounce silver etc, and some of those are also denominated as $1, for which see respective lists; this particular coin denominated as One Niue Dollar is not in a standard ounce-based size.
The Mint says about this coin:
The “Sunny Scarabaeus” constitutes a metaphorical representation of fire and the Sun Decorative glass known as “the desert sand” or “the goldstone” has a warm golden shade and a glittering structure. It enhances courage and fortitude, unlocks personal potential and rekindles spiritual energy. | 
Search for Niue: One Dollar Silver 2021 Solar Scarab on eBay 