Emerald is an excellent heart chakra stone.
Emerald opens the heart chakra and alleviates heaviness and distortions in the auric field, facilitating a sense of emotional renewal. It offers energies of hope, encouragement, gentleness and abundance. On a physical level, it's said to help with spinal disorders, and disorders of the lung, heart and muscular system. It is also said to soothe the eyes.
Listing is for one piece of rough (unpolished) emerald. Pieces vary in size somewhat.