하나의 돌 - Evolution Item
하나지방에서 처음 발견된 특정 포켓몬을 진화시키는 특별한 돌. 블랙과 화이트의 구조가 특징적.
Special evolution items like the 하나의 돌 first arrived back with the second generation of Pokémon, and are now required when evolving Pokémon such as 야나키 and 바오키 and 앗차키 and 몽얌나 and 치라치노 and 저리더프 and 샹델라. When evolving these Pokémon, this item is required in addition to the candy, and is consumed when used.
How to get the 하나의 돌
The 하나의 돌 is obtained from spinning Pokestops and Gyms. There is a very low drop chance of around 1% per spin to receive a 하나의 돌 or any of the other evolution item, and there is an equal chance of obtaining each of the 5 currently available items.
There's no way to ensure that the 하나의 돌 will drop, but with only 4 other items, there's a greater than 50% chance that you'll receive one once you've spun over 250 Pokéstops.
The 7th day streak bonus gives you a very high chance of obtaining one of the evolution item, but it's not believed to be guaranteed.
Other evolution items
The other evolution items that can be found in Pokemon GO are: