Approximately 2.5 inches. Moss Agate helps correct imbalances between the left and right side of the brain. It boosts mental function and can be a beneficial stone for those who lack creativity and imagination. Moss Agate helps one feel grounded,safe,and secure, due to its strong connection with Mother Earth. It is said to be a powerful aid for those who experience frequent mood swings due to its stabilizing properties. It stimulates the heart chakra and promotes emotional healing.