I'm very confident I left another Silver coin a few feet from the Merc.
Exact same signal But there was a Root spike sticking up very close to the center of the tone.
And the object was in Very Deep sticky Mud.
I could not get a signal with the Probe but the Mud stuck to it.
It was also in a field of Poison. (No Gloves)
after a few long bouts of Frustration I got up started walking away Swinging & got another.
This one didn't have a Root over it to bounce my coil off,
But was almost frustrating enough to pass too, & then the probe signaled last second

Yes I will go back if we get a decent dry spell