Most decent detectors nowadays can discriminate Moll,they can tell the difference between ferrous and non-ferrous,get a minelab with an LCD which has a depth indicator etc,the display shows you what the machine interprets the signal as being,coin,ring,junk etc,you also learn your own machines signals,a coin with a high silver content has a very distinct tone totally different sound from a pound coin etc,theres even a detector disguised as a walking stick