Hematite is a stone that is most commonly -- and most strongly -- used to ground or stabilize and for protection. In spiritual work, Hematite is an excellent stone to help keep yourself connected to the Earth plane, as some would say via the "silver cord", so that your spiritual learnings and travels can be done safely, and things learned can be brought back to daily life more easily.
Emotionally, Hematite decreases negativity. This lowering of negativity can benefit by helping balance the body/mind/spirit connection. It also is said to balance the meridians, boost self-esteem, and self-confidence.
Physically it has been used in complementary crystal healing to cool the body, blood disorders, Reynaud's Syndrome, nervous problems, stress and insomnia, spinal alignment, and broken bones. It is also an excellent stone for anxiety relief.