This is a Tibetan Phurba Dagger made into a mobile accessory from brass and plated with gold. You can hang it on your personal objects like mobile phone, handbag and such.
A Phurba, also called a magical dart is a tantric weapon used especially for the ritual slaying of human effigy or foe, to conquer evil spirits and to remove obstacles in Tibet. It is also used as a instrument to store personal power and also for protection against demons.
Carry it with you all the time to ward off evil spirits and negative energies around you.