The Golden heart is an item in KQ5.
This heart is small and golden, and can be found in the Dark Forest from inside the door at the tree trunk. Alicia (as a tree) asked Graham to find her heart for her within the Dark Forest. Once Graham gave the heart to her, she transformed back to her normal self, was reunited with Herbert of Greys, and the two left together.
KQ5: The small heart is made of pure gold.