I just dont see anything worth hanging onto wrt what the healey feelies believe. The fact that crystals have pisezoelectric properties or even slight magnetism for some species, means absolutely nothing as far as their medicinal properties.
I suppose , if you really believe, and dispense all logic, , you can derive healing power from various flavors of ice creams.
It IS big business though. I was at the Tucson show about 10 years ago and it was loaded with these crystal gypsies hawking all kinds of properties associated with THEIR kinds of crystals.