In this video this person states that a GPX missed the gold in the rocks that the Minelab 777xx pickup.
The bucket of material he shows looks like quartz rocks (most of it it seems).
I have some quartz rocks that came from a claim that is heavily minerialized, lots of black sand in the dry creek beds.
Some pertrified wood with some mineral veins and lots of iron pyrite.
My AT Gold does not sound off on any of the quartz rock chunk,s except for one and that is questionable.
The one that is does sort a sound off on is not heavy in quartz, but has a dark red color to it (jasper?).
Lets assume that the minelab would have sounded off on the rocks that i have, but the GPX would not have.
Would my AT Gold have sounded off, same as the Minelab 777xx?
Sensitivity is turn way up, threshold is down.
Did try the AT Gold on Dics 1 with pretty much the same results.
Sometimes i do get a reading of 40 or so, but unsure if that is true or just noise.