Evolution Items

Evolution Items are items used to evolve certain species of Pokémon. There are currently seven items that can be obtained, that are:
 * Dragon Scale
 * King's Rock
 * Metal Coat
 * Sun Stone
 * Up-Grade
 * Sinnoh Stone
 * Unova Stone

To see currently owned Evolution Items player can check them out on the item bag page.

Johto Items
There is small chance that they can be obtained from spinning Photo Disc in PokéStops and Gyms and trainer is guaranteed one on their seventh day spin streak. They can be also obtained as a reward from research tasks and gifts.

Sinnoh Stone
Claiming Research Breakthrough or participating Trainer Battle has a small chance to obtain one.

Unova Stone
Claiming Research Breakthrough or defeating Team GO Rocket Leaders has a small chance to obtain one.

Trivia

 * All Pokémon, that to evolve into them there is evolution item required, normally cannot be neither caught in the wild, hatched from an egg, be a Raid Boss in the gym nor be a reward from research tasks and the only way to acquire them is the evolution.
 * Historically, in the Pokémon game core-series, the following conditions described below will take place when one of these items are given to a Pokémon to hold:
 * Pokémon capable of holding either a Dragon Scale, King's Rock or Metal Coat will evolve when traded.
 * Pokémon capable of holding either a Sun Stone or Up-Grade will evolve when leveled-up.
 * On the official support page for Pokémon GO, Deepsea Scale and Deepsea Tooth were mentioned.
 * In the main series games, these items are required to evolve Clamperl into either Huntail or Gorebyss respectively.
 * This concept was scrapped. The evolution of Clamperl is finally decided to be random.
 * The Sinnoh Stone was first discovered in network traffic on November, 2018.
 * Graphic design of Sinnoh Stone hints that it is made of diamond and pearl materials which is reference to Pokémon: Diamond and Pearl games in which Sinnoh region was introduced.
 * Similarly to Sinnoh Stone, graphic design of Unova Stone is made of black and white materials which is reference to Pokémon: Black and White games in which Unova region was introduced.
 * During Hatchathon 2018, claiming Research Breakthrough guaranteed a Sinnoh Stone.
 * During the February 2019 Community Day, Trainers were guaranteed to receive up to five Sinnoh Stones as a reward from Trainer Battles; in order to evolve their Piloswine into Mamoswine.
 * No Sinnoh Stone was guaranteed on August 2019 Community Day for Gallade evolution.
 * During the February 2020 Community Day, Trainers were guaranteed to receive two Sinnoh Stones as a reward from one set of GO Battle League; in order to evolve their Rhydon into Rhyperior.
 * Porygon family is the only evolutionary line that requires two different evolution items.