A ritual vajra is cast in bronze or brass, occasionally silver, by the lost wax method, a specialist casting trade centered historically in the Kathmandu Valley and in Tibetan monastic workshops, producing the double ended, prong tipped form in sizes from a large ceremonial implement down to a small pendant with far less restriction attached to it.
Always paired with a bell
A ritual vajra is never used alone in Vajrayana practice, it is always paired with a bell, ghanta, held in the other hand, the two implements together rather than separately representing the union the practice is built around, and a set is generally cast or acquired together rather than mixed from different makers.
Who is permitted to use it ritually
Handling a vajra in actual ritual practice, rather than owning one as a devotional object, is tied to initiation, a practitioner is expected to have received specific empowerments, abhisheka, from a qualified teacher, a lama, before taking up the implement in that formal sense. This is a real restriction on ritual use rather than on ownership generally, small vajra pendants are sold and worn widely with no such requirement, and this entry describes that boundary rather than instructing on the empowerment itself.