She and I both have a hypersensitivity to things like electromagnetic fields
No, you like to think you do. Do you have any evidence? Its easy to fool yourself into thinking such things. For instance, when someone turns a TV on often there's a very short high pitched whine as the electronics power up. If your hearing isn't accurate enough to hear it properly you might still notice something and deceive yourself into thinking "I can sense its EM field". Can you tell when your neighbour turns on their microwave? Can you tell which wires have current moving through them and which don't?
I'd believe you if you underwent double blind tests. For instance, two insulated cables run across the table, the sort which connects a lamp to the wall. You're then asked, every 10 seconds, to say which of the two (if either) of them has an active current running through it, ie the connected lamp (which you can't see) is on. The person asking the questions doesn't know either, that way its 'double blind', as any good experiment should be. If you get the answer right a statistically significant higher frequency than random guessing would
then I'd believe you have 'hypersensitivity' to electromagnetic fields. Having low or high potassium isn't enough.
If the pendants have excessive heat or excessive cold then it shouldn't be hard to prove as much. Strap a small thermoprobe to the side of the metal and cover it enough so that the bits not touching the metal are covered up. Get a large container of water and put it in a room which has a well maintained temperature and allow it to reach thermal equilibrium. Measure the temperature of the water (ideally use another probe to get constant readings). Put the pendant in the water, still strapped to a probe and wait for a few hours, to allow thermal equilibrium to be reached, if the metal isn't producing or consuming heat. Then start taking readings of the water temperature and the pendant temperature for several hours.
If the pendant is producing heat out of some 'scalar field' (which I don't believe you even understand the meaning of) then it'll be able to maintain itself outside of thermal equilibrium, it'll be noticeably hotter or colder than the water. Our bodies produce heat from food stores in order to maintain our temperature, hence the same experiment done on a person would reveal we have with us access to a form of energy, this is the same principle applied to those pendants. If it isn't, its just a normal lump of metal, then its temperature will be extremely close to that of the water. And this effect should be visible at almost all temperatures, so if the pendant is producing heat then by cooling the water to a lower temperature the difference between it and the pendent will be even more noticeable.
If you can provide detailed experimental observations which confirm the effect and a reputable lab can then replicate your findings you would turn over
everything overnight. Cheap, unlimited energy would solve so many of the problems the industrialised world has.
The very fact someone isn't making
trillions from this demonstrates that there's nothing to your claim. An effect as obvious as "Hey, this is warm, noticeably so!" wouldn't be missed by people spending decades in labs manipulating every element on Earth (and a few we've made ourselves). Radioactivity was partly discovered because people noticed something made materials warm or would make them glow.