Allagan Tomestones are a currency acquired through high-level duties, the Duty Roulette, Beast Tribe quests, The Hunt, Treasure Maps, and PvP. They can be spent at Auriana to purchase various weapons, armor, accessories, and other misc. items.
There are two types of Allagan Tomestones currently available:
(Allagan Tomestone of Esoterics are scheduled to become available 4 weeks after the official launch of Heavensward)
Prior tomestones are no longer obtainable and have no use, but may be exchanged at Auriana for newer tomestones at a 4:1 rate:
Older tomestones have been completely removed from the game: