Altarianite

==Information==
Location: Azurine Lake
Available: After Badge 13
==Guide==
Go to Apophyll Academy. Then go left and go all the way up.
When you reach the cave, surf up into the opening like in the left photo. Surf all the way up until the map change into Peridot Ward, then surf right into the opening like in the right photo below.
Go all the way down while sticking to the left side, then dive down. While underwater, go down past the grassy area, like in the right photo below, then resurface.
Go into the small opening in the bottom left corner and dive down on the small dive area.