Soul Casket

• Soul Casket
• Item Level 359Disenchants into:
   [Maelstrom Crystal]: 1
• Binds when picked up
• Unique-Equipped
• Trinket
• +321 Mastery
• Use: Increases your spell power by 1926 for 20 sec.
• Requires Level 85
• Sell Price: 8 5 7

Source

This item is sold by the following vendors for 1650 :

•  Faldren Tillsdale <Valorous Quartermaster> in Stormwind City
•  Jamus'Vaz <Valorous Quartermaster> in Orgrimmar

Patches and hotfixes

• Patch 4.2.0 (2011-06-28): Cost converted to Justice Points.
  
• Patch 4.0.3a (2010-11-23): Added
  

External links

• Armory (EU)
• Wowhead
• WoWDB