There are a total five stones to collect on Powerpets, namely the Night Stone, the Ruby Stone, the Sapphire Stone, the Emerald Stone and the Light Stone. These Stones appear on your user lookup under the heading "Achievements" and not in your inventory. In order to collect these stones, players need to fulfill different tasks and prove themselves worthy of keeping them. These stones can also be transferred to your players pets if a certain requirement is fulfilled or an event is triggered.