Cold Forged Hammer

Cold Forged Hammer is a rare mace and a reward for fighting in Alterac Valley.

Source
This item is a reward from the Horde quest which starts with Voggah Deathgrip in the Alterac Mountains, and the Alliance quest   which starts with Prospector Stonehewer in the Alterac Mountains. You can directly complete these quests after you receive them, but you must have completed the quest to get these quests.