The Mega Stones have made a comeback in Pokemon Let’s Go Eevee and Pikachu, this guide will show you how to acquire each of the Mega Stones offered in the titles. It’s worth noting, no Mega Stone is exclusive to either game, all stones can be acquired in both titles.
Charizard, Blastoise, and Venusaur’s Mega Stones can all be acquired at the same location. Head back to Pallet Twon after beating the Cinnabar Island gym, and Professor Oak will give you the Venusaurite, Blastoiseinite, Charizardite X, and Charizardite Y.
Mewtwo’s Stones can be found back in the Cerulean Cave where you had originally caught Mewtwo. You will be rewarded the Mega Stone after defeating Green. You receive both Mewtwonite X, and Mewtwonite Y after fighting her.
Every other Stone is found inside the Pokemon League entrance. A man in a Slowbro costume will sell you the rest of the Mega Stones for 30,000 a pop.
The stones offered are for the following Pokemon,