In Pokemon GO, some pocket monsters simply do not evolve after feeding candy. This is because they require candies as well as a special evolution item. It may be the Sunstone that was first seen in the second generation of Pokemon, Pokemon Gold, Silver and Crystal games.
This item is able to evolve Gloom, Sunkern, Cottonee, Petilil, and Helioptile in the mobile game, but newer players may not be familiar with how to obtain it. It’s fairly easy to obtain, but trainers will definitely need a bit of luck on their side, as many other Johto region development items are obtained in the same way.
If Pokemon GO players are looking for the Sunstone, they will have to go to nearby pokestops.
Getting Sun Stone in Pokemon GO
A guaranteed evolution item can be Sunstone, but it can also be Dragon Scale, Upgrade, King’s Rock, or Metal Coat. Which item you get depends on luck and the game’s random number generation (RNG) at the end of the day. So you will have to keep spinning pokestops until you receive your Sunstone.
Additionally, Sunstones and other evolution items can be obtained from time to time through in-game research. Currently, the only evolution item that Field Research Tasks offers is King’s Rock, but this may change over time as new tasks are constantly being included.
Special research stories introduced during events can also reward evolutionary items under certain circumstances, especially when the chosen Pokémon can benefit from them.
For now, trainers will simply have to spin Pokestops unless Niantic introduces an upcoming event that will focus specifically on Sun Stones and their compatible Pokemon.