Help for Hard Rock noob

[arthos]

Today I visited an old prospect in my area, I collected some samples though I'm really quite new to hard rock. Here is a description of the material from this specific sits taken from a bulletin by California vision of mines 1959.

Contact of diorite and gabbro with (San Marcos gabbro) (Triassic Santa Ana) Shist, Where vein quartz a accompanies a 4 to 6 ft. aplitic dike now much fractured and decomposed, Manganese oxide stains.
I found an interesting spot to sample the quarts vein (from one side of mineralization to the other) There are noticeable small vugs in the rock which i have read can be a good sign.

I do not own or have access to a rock crusher, I tried smashing the sample with a sledge as best I could, down to about a 1/16" mesh panned it but did not see any gold. Should I have seen gold breaking it down do that size or is that simply not small enough? I was hitting it with 5 lb sledge against my garage concrete man that rock is HARD sparking like crazy and i was afraid id damage my garage post tension concrete floor!. Id hate to discard the sample without knowing if I'm just not doing it right!

 

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[Assembler]

Hello
If the goal is to remove near all ‘Free milling gold’ one will have to crush and mill much finer. However if the goal is to start finding any colors and flake size pieces of gold one can try running a falcon probe type of metal detector over the 1/16 inch size samples spread out. One can also try running a gold type metal detector with a 4 – 5 inch coil for say picker size gold. This could cut down on the amount of crushing one has to do to find any gold. Remember this is just sampling to see if one can find any gold at all.
Just because one is finding mineralized rocks does not mean there is always gold inside. There is a reason why it is called “Hard rock mining”.

 

[Assembler]

Hello
If the goal is to remove near all ‘Free milling gold’ one will have to crush and mill much finer. However if the goal is to start finding any colors and flake size pieces of gold one can try running a falcon probe type of metal detector over the 1/16 inch size samples spread out. One can also try running a gold type metal detector with a 4 — 5 inch coil for say picker size gold. This could cut down on the amount of crushing one has to do to find any gold. Remember this is just sampling to see if one can find any gold at all.
Just because one is finding mineralized rocks does not mean there is always gold inside. There is a reason why it is called “Hard rock mining”.

Find a association or club near you and visit to ask if anyone can crush your samples down finer then test pan. May also ask if anyone has a gold cube if you want to run more rock samples.

 

[Assembler]

Find a association or club near you and visit to ask if anyone can crush your samples down finer then test pan. May also ask if anyone has a gold cube if you want to run more rock samples.

If you do not find any gold at all in the samples you have try a new test samples in the near by mineral zones. Remember gold often likes iron so any iron mineralized zone nearby should be checked out. As a plus the iron mineral zone can be a little softer for crushing.
You could be as close as just a number of feet away from fining gold.

 

[SaltwaterServr]

Send it off to have it assayed, then you'll know if you're getting somewhere.

 

[Assembler]

If you do not find any gold at all in the samples you have try a new test samples in the near by mineral zones. Remember gold often likes iron so any iron mineralized zone nearby should be checked out. As a plus the iron mineral zone can be a little softer for crushing.
You could be as close as just a number of feet away from fining gold.

This one assumes that the idea is to find some gold at this time. Finding out how much per ton is a different story.

 

[Nano]

Today I visited an old prospect in my area, I collected some samples though I'm really quite new to hard rock. Here is a description of the material from this specific sits taken from a bulletin by California vision of mines 1959.

Contact of diorite and gabbro with (San Marcos gabbro) (Triassic Santa Ana) Shist, Where vein quartz a accompanies a 4 to 6 ft. aplitic dike now much fractured and decomposed, Manganese oxide stains.
I found an interesting spot to sample the quarts vein (from one side of mineralization to the other) There are noticeable small vugs in the rock which i have read can be a good sign.

I do not own or have access to a rock crusher, I tried smashing the sample with a sledge as best I could, down to about a 1/16" mesh panned it but did not see any gold. Should I have seen gold breaking it down do that size or is that simply not small enough? I was hitting it with 5 lb sledge against my garage concrete man that rock is HARD sparking like crazy and i was afraid id damage my garage post tension concrete floor!. Id hate to discard the sample without knowing if I'm just not doing it right!
View attachment 1467830 View attachment 1467827 View attachment 1467828 View attachment 1467829 View attachment 1467831 View attachment 1467830

I do not own a rock crusher either and I am no geologist. Found too many rocks that give good signals and I just can't do much about it.Noise and dust.I just don't have the
privacy for such things.But I have found rock near identical to that and I crushed a small bit of it with a hammer and did find gold,albeit small and not worth the effort of crushing it vs just working the sluice. But if I had the space and privacy,I would be crushing and milling that rock for sure. Hope you have both mate. Wish I did.So many good rocks. Good luck man. I would find your rocks encouraging for what it's worth.

 

[bobw53]

Making a small rock crusher for small samples is a really cheap and easy thing to do..

A few different size pipes , a cap for the smaller pipe and a steel plate and you should be good to go..

Here is my first "home made" rock crusher.. Just a piece of tube, a piece of rod and a steel plate I had kicking around,
no machining involved, no welding... You're not going to do a ton of rock, but it works pretty darn well and quick on small
samples.

 

[bobw53]

Woops, double post...

And buy a belt.. I had to.. My pants kept falling down from all the rocks in my pockets.

 

[Assembler]

Hello
The idea of any metal detector use is for 'High grading any sample ore'. The metal detector will skip over all the fine gold except the probe type such as a falcon this of course takes time and the samples needs to be spread out.
The idea of any crusher is to free or release any 'Free milling gold' to the point where one can test pan etc. wet or dry. The idea of a impact mill or say a jaw crusher is to test sample larger samples out in the field. If one test samples say a 1/2 ton of rock ore one can get some idea what is there in terms of minerals in the test ore.
Hard rock prospecting is hard dirty work period.

 

[arthos]

Making a small rock crusher for small samples is a really cheap and easy thing to do..

A few different size pipes , a cap for the smaller pipe and a steel plate and you should be good to go..

Here is my first "home made" rock crusher.. Just a piece of tube, a piece of rod and a steel plate I had kicking around,
no machining involved, no welding... You're not going to do a ton of rock, but it works pretty darn well and quick on small
samples.

Thanks bobw53 I may just take a trip to Depot and see if i can put something like that together =D

 

[Assembler]

Hello
This one assumes you have access to many tons of this type of rock? If so try 'High grading a few tons' then work on the higher grade rock samples. This could also help you to determine if you really want to buy some more tools for prospecting.

 

[arthos]

Thanks for all the suggestions fellas! I'll be happy to discover ANY gold in hard rock at this time. I have more sample to work through I'll let y'all know how it goes!

 

[arthos]

Hello
This one assumes you have access to many tons of this type of rock? If so try 'High grading a few tons' then work on the higher grade rock samples. This could also help you to determine if you really want to buy some more tools for prospecting.

"Access" well its hard to say, i have access right now, these workings are in a patch of hills which is quickly disappearing as the housing developers encroach from all sides. Right now its me just poking around at old workings in my area all of which are pre 1930s. But you are correct finding visible free mill gold would make purchasing more tools a lot easier to justify

 

[dave wiseman]

If your using a homemade mortar and pestal,put a piece of old inner tube over the pestal and hold that down over the mortar as your pumping the pestle.That way the rocks don't go flying everywhere.This especially helps when you've some small higrade species,ha,ha....and don't wear yourself out slamming the pestle down,go slow and easy,your a person not a stamp mill.

 

[Eu_citzen]

First of all, get a big piece of cast iron to go with the sledge. Use a forward sliding motion, do not hammer on it, it seems to work better for grinding.
That's how I grind small samples for quick testing. I can easily get to -50 mesh in a 2-3 passes for smaller stuff, screening in between.

One day, I totally need to build a rock crusher for testing larger sample volumes.

Edit: And if you're not on a budget, get an assay done. Then you'll know for sure.

 

[arthos]

So I remembered I do have a piece of plate steel to work with so I went to town with the plate and 3 lb sledge. Did a small batch, paned it out. No gold but lots of this purple colored metal lead maybe? Silver? I still have materal from other areas at the same site to check, will try to give it least 1 more shot looks like those pan pictures came out upside down.

 

[arthos]

The grinding motion was definitely to way to go once it was small enough.

 

[arthos]

First of all, get a big piece of cast iron to go with the sledge. Use a forward sliding motion, do not hammer on it, it seems to work better for grinding.
That's how I grind small samples for quick testing. I can easily get to -50 mesh in a 2-3 passes for smaller stuff, screening in between.

One day, I totally need to build a rock crusher for testing larger sample volumes.

Edit: And if you're not on a budget, get an assay done. Then you'll know for sure.

The grinding motion was definitely to way to go once it was small enough.

 

[Assembler]

First of all, get a big piece of cast iron to go with the sledge. Use a forward sliding motion, do not hammer on it, it seems to work better for grinding.
That's how I grind small samples for quick testing. I can easily get to -50 mesh in a 2-3 passes for smaller stuff, screening in between.

One day, I totally need to build a rock crusher for testing larger sample volumes.

Edit: And if you're not on a budget, get an assay done. Then you'll know for sure.

This is how a high pressure rolls works by the same sliding motion between the rollers.