Question about unexpected Falcon MD20 Mineral Id

Boarteats

Full Member
Mar 25, 2018
134
137
Near Baltimore
Detector(s) used
Falcon MD20
Primary Interest:
Prospecting
Question for any experienced Falcon detector users out there.

Got a new MD20 last week. Has been fantastic. Finding a lot of gold (from hobbyist perspective). Device was easy enough to figure out. However, I encountered something today that I do not understand.

Got a very strong signal from MD20 on a rock that is similar to others that have contained gold. Crushed it, panned, etc. Quite unexpectedly, the material that the MD20 identified as a nonferrous metal in that rock looked a whole lot like magnetite and was attracted to a magnet. In fact, to double check, I pulled material directly off magnet, stuck it in an empty pan, and scanned it with MD20. Strong signal only going toward sample. Nothing when pulling back.

This seems very odd and was wondering if anyone has had similar experiences and/or might have some thoughts on what might be going on. Checked off usual suspects: wedding ring, nearby strong magnetic fields, nearby metal, etc.
 

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Jim in Idaho

Silver Member
Jul 21, 2012
3,313
4,684
Blackfoot, Idaho
Detector(s) used
White's GM2, GM3, DFX, Coinmaster, TDI-SL, GM24K, Falcon MD20, old Garrett Masterhunter BFO
'Way Too Cool' dual 18 Watt UV light
Primary Interest:
Prospecting
That's typical for the Falcon. All the mineral has to be is electrically conductive and you will get a signal going towards it.
Jim
 

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Boarteats

Full Member
Mar 25, 2018
134
137
Near Baltimore
Detector(s) used
Falcon MD20
Primary Interest:
Prospecting
That's typical for the Falcon. All the mineral has to be is electrically conductive and you will get a signal going towards it.
Jim

A bit of a buzz kill, but still a useful tool. Wonder if there are any tools to take magnetic susceptibility measurement of materials in the field.
 

russau

Gold Member
May 29, 2005
7,250
6,701
St. Louis, missouri
What is your main idea here ? If your looking for the lines of flux that the magnets have (North / South ) then try a Milli. Gauze meter. This meter with show the gauze strength ( a unit of electrical measurement ) and the higher the measurement the closer you are to the source. These meter's are very cheap !
 

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Boarteats

Full Member
Mar 25, 2018
134
137
Near Baltimore
Detector(s) used
Falcon MD20
Primary Interest:
Prospecting
What is your main idea here ? If your looking for the lines of flux that the magnets have (North / South ) then try a Milli. Gauze meter. This meter with show the gauze strength ( a unit of electrical measurement ) and the higher the measurement the closer you are to the source. These meter's are very cheap !

Not a well developed idea but general notion is that being able to measure diamagnetism/paramagnetism could help differentiate non ferrous minerals of interest. For example, gold and copper are diamagnetic. Platinum is paramagnetic. Granted, I imagine that there’d be a number of confounding variable that’d make accurate field measurements difficult.

Motivation is that I’m working streams where similar looking rocks can contain nothing but manganese or manganese plus native copper, gold, and/or possibly ferro-platinum. High manganese dioxide content makes crushing and panning quite messy. Would be nice if I could more efficiently triage collected material.
 

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