https://www.gamespot.com/articles/pokemon-go-adding-a-new-kind-of-berry-through-cele/1100-6461294/

The Celebi Special Research questline has begun in Pokemon Go, and along with giving players a chance to capture the Mythical Pokemon, it looks like it will introduce a new item to the game. Dataminers have discovered the brand-new Silver Pinap Berry within the game's code (via Pokemon Go Hub), and it appears to be the reward for completing one of the latest Special Research tasks.

According to dataminer Chrales, the Silver Pinap Berry is effectively a combination of the standard Pinap and Razz Berries. Feeding it to a wild Pokemon will reward you with twice the usual amount of Candy you would receive upon capture. In addition to that, the Silver Pinap Berry makes the wild Pokemon easier to catch.