For instance, you probably feel a little differently in the winter than you do in the summer — more sluggish and less playful, maybe. If you believe in crystals' energetic power, you could very well benefit from keeping, say, a crystal that promotes better and more restful sleep by your side during the colder months. On the flip side, you'd probably enjoy having a bubbly, welcoming stone like citrine handy during the summertime.