We have put these rare and special stones on our Sacred Bone Mala's and have had many people enquirer abut them. They are an agate not unlike the traditional Dzi Beads being extremely rare. They are primarily found in the Himalayas and practioners in that region say the essence of the Great Black One, Mahakala is inside the stones. Each one is around 1 inch and weighs six grams. It has holes at each end and can be strung and worn.