Charizardite X

==Information==
Location: Calcenon City
Available: After Badge 11
==Guide==
Go to Calcenon Gym. At the Gym, reproduce floor pattern in the left photo on the floor of the final area in the gym. The final result should look like in the right photo. This pattern is officially revealed during the story events after you obtain Badge 16, but if you know the pattern, you can reproduce it in the gym any time before that. Therefore, the actual point of earliest availability is after Badge 11, after you have defeated Charlotte and she leaves the gym.
Go into the secret door and go into the back room.
The pattern on the floor and the back room are parts of a larger sidequest. To complete it, see Torchic Special Encounter.