Destroyer Lodestone

You can also craft these in the Mystic Forge:
Recipe is as follows:
2 Destroyer Cores (http://www.gw2db.com/items/19778-destroyer-core-s)
3 Crystals (you get them from the Vendor next to the Forge; 5 for 3 Skill points) (http://www.gw2db.com/items/63695-crystal-s)
1 Bottle of Elonian Wine (http://www.gw2db.com/items/65506-bottle-s-of-elonian-wine)
1 Pile of Crystalline Dust (http://www.gw2db.com/items/19680-pile-s-of-crystalline-dust)
this will give you 1 Destroyer Lodestone