It's getting so ridiculous now as people tend to believe all these gimmicks. If you're well aware of the law of conservation of energy and the fundamentals of quantum mechanics, these so-called energy generating craps are just worthless piece of junks. They're good in boasting what the pendant can do but unable to explain the theory behind.

Diagnostic tool that can measure non-existence energy perhaps? Or probably a diagnostic tool that doesn't exist.
If they are made from some moon rocks or meteorite, that will still make sense. But lava, it is certainly bullshit to me. If they were true, the proximity of volcanoes will be a enormous source of the "non-existence" energy and emits indefinite amounts of em waves and eventually evolves into a sun of its own producing massive amount of heat. End up the earth will be too hot for living organisms to survive.