Agate's most noticeable properties overall are balancing yin/yang energy, courage, protection, healing, and calming. The Metaphysical and Healing Properties Lore of any specific type of agate depend to some extent on the color of the agate, but all agates have certain things in common.
Agate is a stone of strength. It was used by the Ancients on the breastplates of armor to give warriors strength and make them victorious in battle. Energetically, it is considered to give strength in both battle and physically.