Is there any?

[Snee]

Is there any material that blocks or stifles a copper coil's signal? Like if you put a sheet of something under it, it would shut out all signal underneath? Another question is, is there any material that can enhance the individual signal? Like, the way light can be reflected by mirrors, is there something that can reflect and condense the signal into a specific point? I hope what I'm asking is coming through clear... Thanks for your input!

[Snee]

Like, is there any material that is like...Superman can't see through lead, right? Is there anything that a metal detector can't "see" through?
...I don't know, I guess that's all I'm wondering.

[jeff of pa]

Yes, Any Metal.

A detector Signal can't Penetrate (LET'S SAY) COPPER to Find SILVER. & Vica Versa.

? ? ? ? ? ? ? ? ? ? ? I don't think it can Penetrate Certain Minerals Also,

? ? ? ? ? ? ? ? ? ? ? ?As that May be the reason, Highly Mineralized Ground
? ? ? ? ? ? ? ? ?Hampers the Signal reaching deeper targets.

What a Large Magnet, Near a Coil will do, I'm not shure.
I'm not going to try it to find out.