I have a question, i am new to minelabs, i just purchased a used gp extreme, for nugget and lode searching. I have tried and practised with it a few times now, and it seems to work great, once tuned and balanced. BUT, I have couple pieces of gold, and it will not make a sound on them, ive tried almost every setting possible, but Nuthin!!!, the pieces are 1 small nugget at 0.6 Gram, and some natural gold in quartz, total W 6.5G, approx 2-3 grams of Gold in it. My garrett gti2500 screams on them, even the small Nug. BUT the minelab, not a sound, even with both pieces together. I understand thes