If you are just wanting to pick a stone for yourself you should follow your intuition. However, sometimes you may not be able to choose an appropriate stone, Don't worry, let the stone choose you. Simply close you eyes and breath deeply, the stone looking for you will speak to you.
Crystal vibration is the natural vibrational energy that is present in each crystal and stone. It is the energy signature of the stone so to speak. Many people can feel this vibration and use its energy when doing healing sessions. While not everyone can feel this vibration, it is what allows us to work with and manipulate the energy of the human body. Each stone has its own vibrational frequency and can be matched to the vibration of the different parts of the human body. Why, because when we become ill or suffer from the effects of environmental pollution, sound pollution and negative energy from emotional pollution or direct physical damage from injuries, it causes our natural energy frequency to drop or lower. Crystal vibration can help raise our energy back up to help fight off the effects of illness and damage. So you see vibration has an important part in our well being.