Crystals carry their own energy, but they are also highly receptive to energy in their environment. Gemstones will pick up your energy, (i.e. your vibration). They hold your intention and magnify it. Think of how tapes use magnetic energy to record sound, similar to that crystals store thoughts you think/vibrate.
Albert Einstein said everything in life is vibration.
“Everything is energy and that’s all there is to it. Match the frequency of the reality you want and you cannot help but get that reality. It can be no other way. This is not philosophy. This is physics.” –Albert Einstein.