Selenite is an exceptionally useful, as well as beautiful, stone. It's shimmering white, luminescent surface is mesmerizing and calming. It is protective and shields you from negative energies in the spiritual realm.
Much like black tourmaline, selenite will transmute negative energies into positive ones. In fact, it is wise to set a grid around your home using both black tourmaline and selenite That way you have protection in the manifest world, as well as in the spiritual world.
Selenite is self cleansing, but it also cleanses other stones that are placed upon it, or that are near it for a period of time. If you have a box of crystals and stones that you are not "using" at the moment, it is good to place a small piece of selenite in the box to keep the energies neutral and clean. Having a larger piece sitting on a table or shelf in a room where you have many other crystals and stones will help keep all the energies peaceful.
Selenite has a high vibration and it is a great stone to meditate with to achieve higher states of awareness. Some incorporate selenite into their full moon rituals due to its lunar connection. Selenite help one connect with one's guides, guardians, Christ Consciousness and Higher Self. Selenite can be held or placed around a person to facilitate such a connection.