Hematite has been used extensively throughout history. For example, it was the chosen stone for mourning jewellery, worn in the past after a loved one died. Further back in history, it was once a key ingredient in the production of sealing wax and the ancient Egyptians used it to produce magical amulets.
Essentially, hematite is one of the most grounding crystals. It's got an energy of calmness, balance and clarity and can assist with reducing negativity and re-balancing yourself. As the energy is so peaceful and calming, it's often chosen as an aid for helping sleep difficulties. In the same way, it can also be used for meditation and bringing about a peaceful state and clear mind.