I have read that when quartz is heated to a certain temp. it begins to emit electrical pulses. It is utilized in various devices like watches and crystal radios. How is this done and are there more effective or powerful natural crystals or minerals? Where can a layman find comprehensive and easy to understand how-to info. online?
Clearly it is possible if it happened. I do not see any reason for that to happen to a pure quartz crystal, however. The conclusion (in my mind) is that the crystal is not pure quartz, or that the water was not sufficiently pure water (unlikely), or that the crystal did not actually grow. There are a number of minerals that can expand through hydration (anhydrite to gypsum is a good example), and silica does have some hydrated forms (several, actually), but they are not formed from reaction of water with crystalline quartz. It is also possible, but very unlikely at low temperature and pressure in relatively pure water, that there was localized dissolution with reprecipitation (mass moving from one area to another, generally form corners and edges, or small crystal masses, to plate the main crystal on its faces. this sort of thing occurs in nature but requires the SiO2 to go into solution, and SiO2 has a very low solubility in low salinity, pH-neutral waters, so very unlikely and thus very, very slow. Those are some of the possibilities, none seem likely to me apart from hydration of a non-quartz mineral. Quartz crystals will not expand like a sponge when soaking up water.
