No. There are several people who hang crystals around their house, car, neck, etc. who do believe in their healing powers. However from a purely Scientific standpoint they have never been proven to have any healing power other than as a placebo effect.
I think it would be wrong to call it a theory, and very generous to call it a hypothesis.
That’s a ‘no’, by the way.
Of course not. Charlatans have been claiming crap this for centuries. Weak-minded people believe them.
Aren’t those the same people who claim their crystals speak to them?? Sounds like a bunch of bologna!