Generally speaking crystals are not conductive. That is not to say that some crystals, not all, exhibit electrical properties such as the Pyroelectric Effect or Peizoelectric Effect. Most, not all places where crystals are effective in audio systems turn out to be non electrical anyway, you know, like on top of CD players, speaker cabinets, room corners, where crystals’ resonance control properties come into play. In many cases, such as inside electronics and on wall outlets, to name two, it’s their anti resonant properties at play as opposed to anti RFI properties.
