Ewer made from human skulls

Ritual Implements of Bone
One element in the development of Tibetan Buddhism was the spiritual discipline of ascetics, who wandered the funeral grounds of ancient India practicing meditation. To this day, ritual implements made from human bone are a distinctive feature of Tibetan Buddhism.
To Buddhists, human bone is a reminder that life is brief and death inevitable. Bones have other symbolic dimensions as well. Tibetans see the skull as a natural container. Unshaped by human hands, it represents the fundamental goodness that is the natural condition of the mind. Bone trumpets call fearsome supernatural entities. Aprons of bone beads are counted among the funerary “dancing clothes” that signify a yogin’s heroic victory over life and death.

Bone implements are also portrayed in painting and sculpture. In this gallery the goddess Palden Lhamo holds a skull bowl, and Chakrasamvara and his consort as well as the adept Virupa wear bone aprons. , Meditative and Magical Weaponry
Meditative equipment often takes the form of utilitarian tools, especially weapons. These tools are laden with symbolic imagery created to enrich and empower the meditative process. The ritual stake, a tetrahedral-bladed dagger, pins down malevolent spirits. The skull cup and the flaying knife are often paired in a wrathful deity’s opposing hands. The blade of the knife is curved to match the skull’s concavity. Like a mortar and pestle, these ritual tools are used to reduce all ordinary sense-based experience to its ultimate, empty nature, thus obliterating the negative thoughts and emotions that result from the false conception of an independent, substantial self.The quintessential ritual implement of Himalayan Buddhism is the vajra. Its name, meaning “lightning” or “diamond,” denotes the power, speed, and indestructibility of Tibetan Buddhist practice, known as the Vajrayana. In rituals, it is often paired with the bell. Whereas the vajra symbolizes the masculine aspect of the Vajrayana’s spiritual strategies, the bell represents the feminine aspect of its wisdom. Used together, they signify the union of the two, which leads to awakening.