I did not want to get in on this, but now that the ball has been passed:
Crystals are a cool thing. First you need to know what a crystal is. It is a solid where the atoms/molecules/ions or whatever the smallest chemical unit is are ordered in a fixed lattice over long distances. Diamonds are crystals, quartz resonators are, and silicon chips. But what makes them cool for technical use? It is not some magical power, it is the fact that the large-scale order makes them extremely hard (for diamonds) and very predictable in their electrical behavior (for chips and resonators). But chemically, crystals are not that different from their polycrystalline or amorphous counterparts. Diamonds burn like coal, silicon and quartz crystals are as hard to etch as glass. And chemistry is what is behind every kind of medicine that works. So yeah, there are "healing crystals", but their healing properties do not come from a crystal structure, but from the chemicals, whether biogenic or synthetic, that are crystalized in the first place. It is from ingesting chemicals, not from waving around sparkly things, that we get medical healing.