Hand carved in the Himalayas; Yak Bone Phurba.
 
The phurba (Tibetan: ཕུར་པ or ཕུར་བ, Wylie: phur ba; alternate transliterations: phurpa, phurbu, purbha, or phurpu) or kīla (Sanskrit Devanagari: कील; IAST: kīla) is a three-sided peg, stake, knife, or nail-like ritual implement traditionally associated with Indo-Tibetan Buddhism, Bön, and Indian Vedic traditions.