Tulku Thondup says:
Some of the discovered objects are made of unimaginable materials, sometimes eight or sixteen precious materials formed into an image with wonderful artistery. Guru Padmasambhava made many of them miraculously and instructed gods, nagas and yakshas to make others. Some are simple in nature and design, and many were made by human beings.
- Tulku Thondup. Hidden Teachings of Tibet: An Explanation of the Terma Tradition of Tibetan Buddhism. Edited by Harold Talbott. Wisdom Publications, 1999, n.258 p.261.