This set is stamped 925 Sterling Silver. The little ball contains a small little chime which makes a faint sound. What is a Harmony Ball (Mexican Bola). Harmony ball is a lovely piece of jewelry originating from Bali, Indonesia. It is essentially a chime pendant, as the pendant emits a soft but just audible chime sound with movement, and brings calm and relaxing to the wearer. Some call them an Angel caller with its soft chime.