If you take the energy stored in the amulet then you will need to recharge it. By wearing the amulet you absorb the energy inside it. You can learn to recharge it with your own energy over time through meditation and chakra work.
Items that have a lot of energy are moonlight, stones, gems, crystals, sunlight, natural water, alter spaces, herbs, and trees. The list is endless. You might want to start by learning your basics if you haven't already. Basic energy transfers are going to be needed in this quest. You learn them through meditation by learning to gather and redirect energy.