Negativity Blocking Obsidian Mala108 obsidian bead mala with aqua Czech and Hill Tribe silver spacer beads and small sterling silver fish charm. Obsidian is known as a protective stone, blocking negativity and absorbing negative energies from the environment. It is also said to bring clarity and provide support during change. Size: 24 inches around. Fish charm is 1 2 inch. Obsidian beads are 6mm. Czech beads are 5mm.