You will often hear it said that "gold is a low conductor" (d/t the alloys put in it to make 10k, 14k, 18k, etc...). Thus, "gold" will read down anywhere around foil, tab, etc... But this fails to take into account the size of the item. This would only be true for coin/ring sized items (of which, admittedly, most gold is found in items of this size, right?). But trust me: A $20 gold piece reads up around zinc or copper penny. And I bet it you had a solid gold bar, as big as a brick, it'd read up at silver dollar
An example of this phenomenom is to take a small finger-nail size piece of aluminum can. Wave it in front of a TID detector. What does it read? Probably around foil or nickel, right? Now take a tab, off an aluminum can, and wave it. What does it read? low to mid-range tab, right? Now take an ENTIRE aluminum can and wave it. What does it read? penny/dime or quarter, right? But wait! At no time did the composition ever change. In EACH of those tests, the item was still aluminum, right? Only the
size changed. Well, the same concept is true for gold. And unfortunately, gold and aluminum share the same conductivities, per their size.
If anyone tells you they can tell gold from aluminum, based on sounds or tones (softness or roundness of sound) or smears on the XLT bars, or particular TID's, and any other such way to know aluminum vs gold, then do this: Take that person out to the nearest blighted inner city junky park. Turn them loose, and see how much gold they dig, while leaving the aluminum in the ground. I bet they abandon those claims quickly
