Many people explain the healing power of crystals according to their structure which means that certain frequencies will predominate from them. It is the frequency response of quartz, for example, that makes it so useful in digital watches. However, the vibrations that crystals supposedly emit when they are used for healing purposes make some people feel dizzy. In some cases, people will even feel nauseous when they are in close proximity to a healing crystal. This is often explained as a physiological reaction to the crystals vibrating interplay with an individual's chakra. It could be that there is an over-stimulated response in some people, just like the way others barely notice any effect from crystals. If you feel dizzy from a healing crystal, then be careful with it and either use it less or not at all. Most people find that dizziness is down to one type of crystal - not all of them - so some basic experimentation should be all that is needed to solve the problem.