It is my belief that crystals bring out and accentuate who you are. If you have a "bad" experience, you have to ask yourself why...what is it teaching or showing you about yourself? If it is giving you pain, it may be that the crystal is so full of information that you have to take it in small doses. If you feel it is evil maybe it is showing you a part of your shadow self that is negative and needs to be addressed. We all have good and bad within us if we project it to the crystal it is a missed opportunity for self inspection! Love and Light!