Dragon Hearts

The hearts of dragons are more than just an organ, it is a veritable mana-pumping engine that can function outside the confines of their bodies, leaving them still alive. The Flight of the Dragon Knights saw the death of many dragons, large and small. Once their corpses were harvested for materials, such as the scales and hides for armor and their claws and teeth for weapons, their hearts were recognized for their immense magical potential.
  A mage could live off of a preserved dragon heart of medium power for decades, or use it to fuel experiments and research projects for many years. And while it is not strictly classified as a magic item, it was decided that they were close enough to fall into the category.
  To be gifted a dragon heart by its owner is considered a monumental honor and an unparalleled sign of the trust the bestower has in the new owner.