
You need to go to the main menu and choose Mystery Gift. You get this from the event Torchic that is being distributed via Mystery Gift until January 2014. It costs 1,000,000 - 10,000 Pokedollars depending on how stylish you are and is only available every three days. If you didn't get it from him, you will be able to buy it from a man in the Stone Emporium in Lumiose City. When you get to choose one of the former starter Pokemon from Professor Sycamore, pick Squirtle and you'll get this Mega Stone. It can be found at the Chamber of Emptiness, which can be accessed via Route 22. This one can only be found from 8 - 9 PM. The man is standing next to a fisherman and the island is just south of the Sea Spirits Den entrance. Go to Azure Bay and you'll find an old man on an island who will give this to you.

You can find this Mega Stone on B3F of the Reflecting Cave. When you enter Cyllage Gym, go to the right and climb the first wall, then climb the next wall on the right. This one can only be found from 8 - 9 PM and is exclusive to Y. AerodactyliteĪ scientist in the Fossil Lab in Ambrette Town will give it to you once you have returned from the Glittering Cave.

If you defeat your rival in a battle in Kiloude City (which is postgame), he or she will give you their spare Absolite. This one is given to you if you talk to the Abomasnow you saved at the end of Frost Cavern. Sycamore in Anistar City's sundial and he will upgrade your Mega Ring. He or she will be at the pond at the top of the town if you use the Battle Maison for a while. To upgrade your Mega Ring, you must firstly defeat your rival in Kiloude City. Note that most of the Mega Stones require your Mega Ring to be upgraded to appear.

If you want Mega Stones in X and Y, see below For Mega Stone locations in OR/AS, click here! You can find all of the old Mega Stones in OR/AS too.
