Talk:Gengar/@comment-31588552-20170513051446/@comment-33971231-20170513053424

There is a 1/100 chance to find any Mega Stone being held by the next wild Pokémon you encounter.

There are a total of 43 Mega Stone in Project: Pokémon.

That means (1/100)*(1/43) which equals a 1/4300 chance to find a Gengarite being held by the next Pokémon you encounter.

tldr: There is a 1/4300 chance (0.0232% chance) that the next Pokémon you find will hold a Gengarite