This topic is long fossilized, but I'll still chime in:

"crystal healing" aka "lithotherapy" is motivated by superstition, and can be simply explained by placebo effect: indeed, some people do certainly report experiencing positive sensations or feelings (which are in essence subjective), and of course they're not making things up...or at least not consciously.

It is important to understand that "personal experience" does not constitute a proof of anything: as an example, as a kid you were afraid of a monster under the bed. You did experience genuine fear, and even physical effects, such as sweating and increased pulse as a consequence. Yet, this is no proof that there was a monster under the bed.

I've been through at least two studies which clearly proved so called "crystal energy" to be a placebo, one of which was a double-blind study involving quartz versus glass as placebo, if I recall correctly. But let's be realistic, that won't change the mind of believers (since beliefs are not motivated by logic, and thus cannot be challenged by logic alone), and certainly not the one of sellers as this is easy lucrative buisiness.

Placebo effect can sometimes be beneficial in the case of partly subjective symptoms: as an example, remember when your headache stopped only 5 minutes after you ate that aspirin pill, while this molecule actually needs some 30 minutes to reach the blood stream and exert any kind of action, well it was placebo related relief before even that the aspirin did its job. Which is cool. But please, let's just call a cat a cat. It's placebo and that's fine, but it's certainly not a matter of "crystal energies".

But let's also remember that placebo cannot help with physical consitions (i.e. you could be administrated a ton of placebo, but it still won't make your tumor disappear, because the tumor is not subjective, it's tangible). Besides, placebo effect is unpredictable, and there is even such a thing as nocebo effect (as an example, "bad spells" amongst cultures that have strong belief in sorcery).

On the other hand, there are a few minerals that have actual proven medicinal properties when ingested or applied on skin, but this has nothing to do with some kind of "energy", it's simply due to their physical or chemical properties (for instance, clay minerals). It should however be outlined that there are also quite a few minerals which can prove seriously toxic when ingested (or when breathing the dust).

Excellent post.
Anecdotal reports are simply that....they are not based on universally accepted facts or research, therefor attributed to placebo effect.

But I am a firm believer in "Anything one believes to be real is real."

I often wish I was more of a believer. I look at everything through skeptical eyes.

You want crystal healing? Yttrium orthovanadate is grown as monocrystals for use in lasers and makes a beautiful gem. Recent research has also shown that, when ground up and applied to wounds (much like a medieval poultice) it promotes healing and reduces scar tissue formation. So you might say they had the right general idea, just the wrong crystals.