Black Agate is used for Protection, Courage, Success. ... Black Agate is excellent as a healing crystal for respiratory issues, eases nausea, indigestion, cramps and problems of the teeth and gums. Agate is used for treating dizziness, headaches, as well as skin problems. Yellow amber has been used traditionally by natural healers to improve memory, increase mental flexibility and create balanced decision-making. Amber has also been used, historically, as a talisman for courage and self-confidence, and was thought to bring good luck to warriors in battle. 8mm beads, standard size.