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I'll disagree with Camilo Rada's answer, and show that there is definitely a magnetic anomaly. We start with the interactive geophysics map of Geoscience Australia, Australia's federal geoscience agency. Our region is this: Here's the same area with magnetic intensity layer turned on: You can see a clear magnetic anomaly in this area, and it's actually ...


5

The Mount Jim in your map seem to be the one located at 36° 55' 17" S and 147° 13' 01" E. Although, magnetic anomalies are not mapped over the whole worlds, the World Digital Magnetic Anomaly Map provides the best compilation, and there is good data around your area of interest. I've loaded the magnetic anomaly data of the World Digital Magnetic Anomaly Map,...


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Broadly speaking you are correct on both counts: magnetite is the most magnetic mineral, and it can oxidize, first to the matastable phase maghemite, and ultimately to the fully oxidized haemetite. This process can yield grains with a zoned appearance, both in hand specimen and more clearly under the microscope, with brown on the outside and residual black ...


3

Your specimens appear to be goethite. The map below shows mines from Mineral Resources Data System (MRDS) where goethite has been reported.


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Your question is quite similar to one that I asked some time ago, with the additional requirement that the glue be insoluble in water, which unfortunately excludes sodium and potassium silicate. Like you, I've found Ceramabond (albeit 571, not 569, in my case) to be too magnetic. I suspect that there's an element of random variation here. It's not (as far as ...


2

It's not possible to tell what it is from this photograph, but from the limited information given, my first guess is a coarse grained gabbro with large phenocrysts of pyroxene.


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Try to look with a magnifying glass or a hand lens. Do the golden things look like cubes? If yes, then this is most probably pyrite. This is most probably pyrite even if those are not cubes. The colour of some of these looks a bit like chalcopyrite, which is iron-copper ore. Try to smell the rock. Can you sense any sulfur? If yes, then it is probably ...


1

Near to the Earth's surface there are small variations in the Earth's magnetic field, but these don't play a role in providing the magnetosphere which protects the Earth from charged particles emanating chiefly from the solar wind.


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