Zodiac Stone: Gemini, Virgo
Black Agate is a powerful stone because it has a very strong grounding energy which can help in reducing stress and tension. It can also provide relief from grief and promote a calm mind. It can also facilitate one's balance by focusing on tasks at hand. This makes them more efficient in accomplishing goals.
Black Agate has the ability to absorb negative energies before they manifest into reality, so it is also known as a stone of avoidance rather than manifestation. This stone can be used to bring insight into internal conflicts, which will help one see what the cause of their problems are. Black Agate can be used to eliminate confusion, aid in decision making and help one move past denial.