maghaemite (gamma Fe2O3)

[Anonymous]

I like to purchase a P.I detector of some description but I've been led to believe maghaemite (gamma Fe2O3) may interfere with a P.I. detector like say in the case of a Pulstar MP20's performance.
Is this a common trait in a P.I detectors ability?
Is there a low cost P.I detector out there that is less affected?
Does a soil have to have really high concentrations of maghaemite (gamma Fe2O3) or just a little to cause problems to a detectors ability to perfrom in such conditions?
Hardnose

 

[Anonymous]

Hardnose, all PI's are affected by maghemite, more or less equally, unless they incorporate ground balancing as a feature, which very few do. Maghemite is usually not much of a problem on beaches, but most Australian gold prospecting areas are high enough in maghemite that a regular PI would be almost useless.
In the U.S.A., some areas of the desert southwest, and some hardrock mining areas of the west coast and mountain states, are low enough in maghemite (etc.) that a regular PI can be usable. But even then, for gold prospecting a good VLF unit will usually be superior.
--Dave J.

 

[Anonymous]

[No message]

 

[Anonymous]

Maghaemite is a commonly occuring mineral in soils and rocks. In normal soils it can be formed by bacterial action or the action of heat on less magnetic iron minerals. i.e. crop burning and forest fires. In certain areas of the world, such as Western Australia and parts of Victoria, there are very high concentrations of Maghaemite which make a PI detector impossible to use unless it has active ground balancing. Maghaemite, on normal soils and less mineralised ground does give a signal, but with a little practice and good search techniques, it is not a problem, especially if the PI detector is a motion mode type where the receiver is constantly adjusting itself to counteract background signals.
Eric.

 

[Anonymous]

[No message]

 

[Anonymous]

What are the different methods for p[reparetion of gamma-Fe2O3?