Aquamarine can be charged by keeping it in the moon light for the whole night. Full moon light is very beneficial for charging the stone.
For best effect always wash the stone and then dry it in moonlight.
It is recommended that before wearing this gem stone, hold it close to your heart and then think that a white light is emerging from aquamarine stone that is merging with the white light from your heart chakra. Then pray to the aquamarine stone in heart to give you the best of its properties. Now open your eyes and if you feel that the stone has understood you then wear it.
To keep the stone in a good shape wash it with water plus very soft soap but do not do this daily. Also keep it away from heat as heat changes the color and properties of the aquamarine.