A lot of questions in people’s mind, how do we judge if the amulet is powerful and what is the process of the amulet? First, we must understand that making of amulet does not comes from Buddha’s teaching. For making and wearing of amulet is what we called wicha（玄术）. The purpose of wicha is to protect and grant what you wishes. My first master who teach me the path to Buddhism is thru introduce me Thai amulet. I remember that he told me there is no amulet in the world will give you forever life, forever wealth and forever healthy. The main motivate is to protect you from harm of spirit and less of your suffering in this world.
What type of material is use in making amulet? It depend on what material gather by the master in involving making the amulet especially what they intent to give to the wearer. Example: Ajahn Chum (Wat Kao Or), he will use fragment of the brick from histrionic kru, temple soil and even gold dust to make Khun Paen. He choose the material that would brought wearer great fortune and wealth. Some master like Luang Phor Derm’s mitmor using coffin nails to do it, not because of spirit. But because there is lots of coffin nails left after the body of the decease being cremation. Nobody would dare to use the nail for other purpose. In order to solve this issue Luang Phor Derm uses the coffin nail and remake them into mitmor. For wearer to carry for protection.
A lot of people thinks that an amulet that is not conceive does not carry any effectiveness and they either throw away on the floor. Well, it is true that when an amulet is not proper conceive may invite evil spirit to reside in it. However, you must not anyhow discard it. When the object carry the image of Buddha or Gods you have to treat it with due respect. What you need to do is to bring the item to the temple if you don’t want it anymore.
What will happen to the item when they are given to the temple? Temple will choose a date and use the material mix with temple material to remake it into a new amulet. They will not waste the material.
People may ask will there be any harm in wearing an amulet not proper conceive. You see people wear Buddha make of jade, gold, etc. not conceive by temple. Any harm on them? No right.