Gold detectors specifically, metal detectors tuned to the frequencies for finding gold are available from many quality makers and regularly cycle through ebay. The brand of detector you buy and the model depends on the specifics of what your target is.

 

Two catagories exist in detectors: VLF or Very Low Frequency and PI or Pulse Induction, both types can effectively prospect gold nuggets.

 

 VLF detectors descriminate much more effectively the non-target metals, so that less general digging is necessary.

 

PI detectors on the other hand have some advantages over VLF detectors under certain circumstances. PI detectors have increased depth of detection and they are not disturbed by severely mineralized ground