Guild Wars 2

You can buy them for 200 dungeon tokens at the dungeon vendors.
“An offering used in dungeon recipes.”

Anyone know any of these recipes?

See:
http://wiki.guildwars2.com/wiki/Offering_of_Baelfire

and the like for the other ones. Looks like they’re all used to make accessories.

They are used to make various trinkets but you need to get the recipe drops from the respective dungeon first.

Also, this:

Martin Kerstein.3071:

Fractal Relics (the regular ones) have been removed from Mystic Forge recipes. Those recipes now use Piles of Crystalline Dust instead.

With regards to dungeon tokens and crafting: You can buy Offerings from the vendors that sell you the dungeon armors and then use them in the crafting recipes.

Hope that helps

So basically, the Offerings replace the dungeon tokens (since those can no longer be used for crafting since the introduction of the account wallet).