I'm not a prospector but I tried to play one yesterday.

[BarnacleBill]

Here's the content of a post I made on the X-terra forum yesterday.


[Subject: A tough little lesson on ground noise.



Last evening I received a call from a family friend that had lost a 1/4 carat diamond stud earring. The location was a newly completed outdoor athletic facility that was finished this past spring which has several soccer pitches(UK).

I had agreed to meet the lady at noon today and had asked her to bring along the remaining earring so that I could take a reading on it. On board the Barnacle Buggy I had brought an X70 with HF concentric, X50 with HF DD, and a Fisher Edge with 5.75inch coil. The earring turned out to be a yellow gold fairly standard sized stud.

First order of business was to crank up the sensitivity to max on each machine and air test the earring for ID. The X50 showed a "+3", the X70 a "+2", and the Edge a "+12". I noted the disparity in ID on the Fisher.

As this athletic facility is new it consists of sand & gravel with a very thin layer of loam to seed the grass. I then GB'd each machine and placed the earring on the ground with the X70 GB'ing at 12 as a point of reference.

With the Edge GB'd, sensitivity @10 and in All Metal mode the earring on top of the ground ID'd as iron in the -15 to -20 range. Next with the X50 GB'd, sensitivity @20 in All Metal the earring on top of the ground ID'd as iron hitting -6,-9. Lastly I had the X70 in Coins mode All Metal with sensitivity @30 and the earring ID'd once again as iron. I changed locations and re-checked just so I was sure I was not losing my mind.

The upshot is that only with the X70 in prospecting mode and Iron Mask at 5 could this earring be distinguished from iron, and this is laying on top of the ground not below it. I searched for several hours in Prospecting mode but did not find the earring. Unfortunately when the fill had been trucked in, they trucked in trash with it, and it was not the most enjoyable couple hours I've spent with a detector.

It is a sobering thought to know that without using Prospecting mode or digging every target in Coins All Metal mode that I am walking over earring studs that are simply invisible.]

I ran Max sensitivity, because even air testing an inch was about as far away from the coil I could get, to have a good signal on the earring.

As you can see I gained new respect for the amount of patience prospectors must have.

HH
BarnacleBill

 

[wheelbubble]

Say bill I thought I was the only one trying for the stud earrings...I 've tried a lot of combinations to find them and hit on a real good combo,I must tell you that I'm a nugget shooter and a little exp. counts with the tone...I use a gp 3500 with a commander 8" mono coil...I've found numerous stud earrings...most studs will not penetrate the roots coil must be at least 3 to 4"s above the grass or dirt,they will sound like nuggets...

 

[BarnacleBill]

Thanks Wheelbubble, I think I'm going to need to practice with the X70 some more to see if I can develop a functional method. Right now I have no good reason to invest in a 3500, but I hear it is very good at what it does.

Last spring with the X70 prospecting mode I found earring backs easily, but this makes me think I left behind the best part of them. This is part of a post I did, "It took about 30 minutes to move ten feet because stud earrings and backs(14) were coming up one after the other."
But the stud earrings found in this instance were silver or costume type, not gold. However, it was obvious that the area is carpeted in them, and despite being an area hit by other detectorists, their machines just can't see the targets. I wouldn't doubt that there are several hundred gold studs just under the beach sand there.

HH
BarnacleBill