"Mani" comes from the Sanskrit sutra "six-word Dharani" (Om Mani Padme Hum). Because of the stone engraved with "mani", people call it "Mani Stone" for short. Many people would think the Mani Stone is a derivative of Tibetan Buddhism, but that is not completely correct.
With a great depth of aesthetic factors and characteristics, Mani Stone has become a unique Tibetan carving art. Devout Tibetan pilgrims believe as long as they engrave the six-word Dharani on the stones and chant the words day and night, those stones will be enabled supernatural spirits and bring them good luck and happiness. As people continually engrave the stone, there're more and more mani stones heaping together, which form Mani stone mounds and Mani walls.