Help investigating and identifying

[deb]

Good morning guys.
So yesterday we stopped at a random spot for 2 hrs of prospecting before heading home. There were no diggings at this random spot. My detector kept giving very low signal with every step. There was a little quartz and a few stones that went off its nah na with the detector. At the time there was no visible gold and the stones weren't your normal quartz. So i popped them in my bag anyway. When I got home I had a look with my loupe and the is fine flour gold spotted throughout stones. 2 in particular were weighty for stones that size. But they don't look like something I would expect to have gold in or for the detector to pick up that fine a gold. They also have like tiny little black gems which turn green with the light or blue. One in particular big stone went off it rocker with the detector. But on the right side with a pin pointer nothing but the opposite side goes nuts. Can't see anything on it? Gonna break them open. My question would be do you think I should investigate this spot further?? And what type of rock is these?

 

[mbasko]

Unfortunately there are a number of mineralised rocks that will cause a detector to signal. This is more apparent with VLF type detectors like the Equinox & is why a PI (Pulse Induction) detector is preferred in mineralised areas, although even PI's aren't completely immune to mineralised "hot" rocks either.
From the photos it's hard to tell but some do look like a type of basaltic rock I see in some areas that do upset any detector I've ever owned.
The black gems could be, (especially if basaltic), augite or olivine?
The "gold" may be just pyrite? A pin would fracture it rather than indent as a simple test if able to do under a loupe. Without crushing & panning off it could be hard to tell.
An easy way I check is by breaking any signalling rock with my pick. If it's due to mineralisation the signal will either remain in all the larger pieces or dissipate altogether. If gold though it usually remains strong in one piece.
Gold specimens with finely disseminated gold though are harder to identify using this method & crushing/panning is best if you do believe it's gold. High frequency VLF detectors can pick up specimens with finely disseminated gold so it's a possibility.
Obviously some mineralised quartz in there too, which if they were in a known gold area, I would be pretty keen to crack open to check them out. I can't ever recall finding quartz that makes a detector signal that didn't have gold in it but they have all been in known gold bearing areas.

 

[deb]

Unfortunately there are a number of mineralised rocks that will cause a detector to signal. This is more apparent with VLF type detectors like the Equinox & is why a PI (Pulse Induction) detector is preferred in mineralised areas, although even PI's aren't completely immune to mineralised "hot" rocks either.
From the photos it's hard to tell but some do look like a type of basaltic rock I see in some areas that do upset any detector I've ever owned.
The black gems could be, (especially if basaltic), augite or olivine?
The "gold" may be just pyrite? A pin would fracture it rather than indent as a simple test if able to do under a loupe. Without crushing & panning off it could be hard to tell.
An easy way I check is by breaking any signalling rock with my pick. If it's due to mineralisation the signal will either remain in all the larger pieces or dissipate altogether. If gold though it usually remains strong in one piece.
Gold specimens with finely disseminated gold though are harder to identify using this method & crushing/panning is best if you do believe it's gold. High frequency VLF detectors can pick up specimens with finely disseminated gold so it's a possibility.
Obviously some mineralised quartz in there too, which if they were in a known gold area, I would be pretty keen to crack open to check them out. I can't ever recall finding quartz that makes a detector signal that didn't have gold in it but they have all been in known gold bearing areas.

Many thanks for your reply. It was roughly in a town gold known area but no diggings or mines were we were. And i wouldnt say it was highly mineralised and I know roughly about hot rocks etc. That's interesting that it could be olivine never thought of that. The only quartz that was there were alot of the tree roots bringing it to the surface other than that nothing else. I just followed the quartz from the bottom up after going around the base of the slope. Im pretty sure It's not pyrite as pyrite shines in the light but dim out of it. Gold stays yellow either way. So I'm pretty sure it's not pyrite. You can see the yellow flake in the picture attached which I thought gold. I'm going to crush and pan it just to see out of curiosity. I am using a gpx5000 for detecting. I'm still trying to teach myself different rock types so Very interesting info.thankyou again for your reply.

 

[mbasko]

It's sounding promising being in a gold area but it's very hard to give a 100% positive "that's gold" off the photos.
Crushing & panning is the best option. Hopefully you're onto some gold.

 

[geof_junk]

Attachments​

• 
  20240415_075717.jpg
  527 KB · Views: 3

Looking at the target it appears to have worn edges which make me think it is more likely gold than pyrite. Lets hope luck is on your side.