Crystals are Mother Earth's gifts to us, formed within Her body, they are living energy, in a way they are the keys to the Universe. Each particular type of crystal or mineral can be seen as a key, and we can use these keys to access specific energies, whether that be for healing, meditation, protection, understanding, as well as a thousand other uses
We all have our own life/energy force, and we have energy points called chakras. We have seven major chakras, each has a specific function, when we're tired, stressed, unwell or depressed our chakras can slow down or even stop working (which really isn't that uncommon in the stressful society that we are a part of).
Thebest way is to let your intuition guide you, if you feel really drawn to one piece that’s the one for you.
It can be incorporated into jewellery or be raw pieces.
Crystals in their natural form are the most powerful. When crystals are cut, shaped and polished they can lose their natural force. However if the piece you like has been shaped and polished working and wearing the stone will bring energy and life back to the stone and it will perform its natural function.