Don Tyler here, I did a test on hearing gold rings by placing them on the ground using stock coil on v3i on coin & jewelery factory setting. 10k 14k 18k most of the smaller 10 & 14k gold rings gave a low tone and read 3+ to about 18+ mid size rings gave a high pitch and ran up to about33+ to 53+ the largest ring 14 gram 18k rang off at 58+ high pitch. It shows me that as in water detecting to dig everything.