As you improve your renown with the Khaz Algar factions in World of Warcraft: The War Within, you will unlock new items to purchase from the quartermasters. But that doesn't mean that you don't get any free rewards. Aside from Harbinger Crests and Resonance Crystals, you can obtain up to 10 Earth-Encrusted Gems. This item binds to your Warband, which means that any of your characters can use it.