Every energy producing thing in itself does produce vibrations, which is why when we are in contact with "paranormal" our hairs stand up.
I think we open our selves up to higher vibrations when we are emotionally geared to it or are emitting enough for the unseen to attempt to convey or communicate with us. ( through both non FM and FM frequencies as well as visual), but all in all it all comes and is produced from energy. While minerals and stems of crystals do not hold the energy for a substantial enough time to reproduce it.
While I think minerals such as crystals can indeed be a catalyst for transferring and or magnifying or absorbing energy, on its own it is a conductor, and must have the energy directed at it or through it, in order for it to absorb or change the intensity or shape of the energy.
I think we through the power of mind open up our selves to a higher vibration which can accelerate the method of contact, but ultimately does not produce the energy, unless at our higher level we are transposing it (i.e. poltergeist activity with younger individuals who do not have the mental block of limitations )
In regards to the apparitions in antique and outdated clothing, I believe the energies chose how to project them selves and do so by choosing what was known to them in their lifetime, whether it be when they were a living child, or living adult.
What I find interesting is that activity increases during geomagnetic storms which are the opposite of the theories of why activity ceases during the day ( frequencies and EMF fluxes). These geomagnetic storms both increase at intervals randomly which interferes with electrical conductivity and frequencies, so could not these energies chose to manifest when we are listening or less likely to interfere or could it be we are simply to distracted with all the visual stimuli and noise of our everyday life, to simply pay attention to activity that is happening all the time around us?
Further, I think we mentally can project and see what we want to see to a certain extent, which is why evidence is so important. Cameras, EVP recorders and thermal imaging help us confirm or adjust our interpretation of what we are experiencing. As humans our mind naturally can distort or fill in the blanks to what we do/dont hear or see.