"Strange" occurrence in rocks

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PowerSB

Member
Joined
Nov 13, 2011
Messages
10
Greetings everyone
Will try to make this post as short as I can, hopefully finding an answer to a dilemma me and a friend have about a place with so many different types of rock . This area was known for silver and gold(silver with high gold content known in lat. Argetum de Glama) mines in history (many, almost completely covered, mines in vicinity of where I took the pics). What was interesting for me was this white “stuff” oozing from rocks. There was one with black and one with red color also (red colored mineral makes a stream a bit further completely red). Could these things indicate rare minerals? A bit higher is blue clay with some other very rusty looking material (which I panned and got some good amount of black sand)! Any explanation would help us give it a rest and forget about it or do something about it! Unfortunately we don’t have the place to send material for assaying nor find someone to help us identify the rocks/minerals (we really tried even by giving stones/ore to people claiming they can figure it out which they didn’t) and neither of us have any knowledge about rocks and ores. There is a book telling the amount of gold and silver produced every year from these places (in early XIV century) , but not even one explanation on what does the ore looks like nor how was it all treated. All this takes place in my friend’s property. I’ve compressed the pictures so they don’t take much space so could be a bit unclear if zoomed!! Any question i will be more than happy to answer!!
 

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Brown to red is iron hydroxide. White mineral that is forming around ore rocks are often gypsum. It points to some sulfide minerals weathering and forming iron sulfate from pyrite.

Göran
 
Goran has the best answer you are going to get without having a geologist look at the rocks.

Often the precious metals report to sulphides in the original deposition, they will now report to the decomposition products of those sulfides.

A simple test you can do is to contact the samples with 50% hydrochloric acid, at room temperature it may take weeks, if simmered it may take days.

After the samples have been dissolved to the point where no more dissolution takes place you add a lot of water to dilute the residual acid and pan the residue. If no precious metals show in the pan you are not going to get values in a proper fire assay.

Deano
 
Thank you Deano!
Didn't bother with those colorings on the stone, but did take a sample from a almost black/dark blue stone on vein with really shining gold looking stuff (was sure its pyrite or something similar). Roasted the sample, smashed it as much as i could, nitric bath and then AR. Used iron sulfate to precipitate and the result was white substance at the bottom (maybe lead) and black/dark red :shock: liquid that wont settle. Forgot to test for silver :oops:
In future will have to do what you suggested for testing!
 
Greetings everyone
Will try to make this post as short as I can, hopefully finding an answer to a dilemma me and a friend have about a place with so many different types of rock . This area was known for silver and gold(silver with high gold content known in lat. Argetum de Glama) mines in history (many, almost completely covered, mines in vicinity of where I took the pics). What was interesting for me was this white “stuff” oozing from rocks. There was one with black and one with red color also (red colored mineral makes a stream a bit further completely red). Could these things indicate rare minerals? A bit higher is blue clay with some other very rusty looking material (which I panned and got some good amount of black sand)! Any explanation would help us give it a rest and forget about it or do something about it! Unfortunately we don’t have the place to send material for assaying nor find someone to help us identify the rocks/minerals (we really tried even by giving stones/ore to people claiming they can figure it out which they didn’t) and neither of us have any knowledge about rocks and ores. There is a book telling the amount of gold and silver produced every year from these places (in early XIV century) , but not even one explanation on what does the ore looks like nor how was it all treated. All this takes place in my friend’s property. I’ve compressed the pictures so they don’t take much space so could be a bit unclear if zoomed!! Any question i will be more than happy to answer!!
The white material is Kaolin, which is hydrothermally decomposed feldspar.

The black and the red material is what was being mined for its Gold content.

The very rusty material is also what was being mined for its Gold and silver content.

The black material may well contain both gold and silver.

The blue clay is most likely decomposed Galena, which is what the blue-gray clay of the Comstock Load was, and it assayed anywhere from 200 to 400 oz per ton Silver.

Have the black sand assayed as well.

A Greenhorn from Arizona sent me some drywasher concentrates produced from desert sand for an assay. It was mostly black sand with no visible Gold. It assayed 8 oz per ton Gold. ... He asked if that was good.

We will be able to provide assay services again starting next week.

We figured these slideshows may be helpful too.











Ore Deposit Charts: Formation, Structure and Mineralogy

We hope that we have been helpful.

Sincerely; Rick & Carrie
of Geotech Analytical
 
Rick and Carrie, if you would put a narrative to your videos, I think you would be on to something that may help a lot of people who visit this site. Although this is more of a refiner's site, it seems there is more and more prospecting traffic being seen here. Are the moderators cool with this?
 
Rick and Carrie, if you would put a narrative to your videos, I think you would be on to something that may help a lot of people who visit this site. Although this is more of a refiner's site, it seems there is more and more prospecting traffic being seen here. Are the moderators cool with this?
We can do all that and then some. We planned on such anyway.

I seriously doubt any of the mods would have an issue with us doing anything that would help out the Greenhorns among us.

We are aware of the prospecting traffic here.

Quite honestly; I have helped plenty of it here back in 2009 to 2012 on my other account as Richard36.

The prospecting section had little for posts or content.

The thread Goldbug University is my, and now our contribution to this site and the prospecting community here.

I have always been "The Rockman" and always will be.
 
So I would like to say that I fell berry blessed to find this page I have Ben prospecting close to 40 yeare an study's geology learning an searching the mouton crreeks studying busting every kind of rock an studying on it through a 300x lend running the different field tests to track it to a mineral class close as I can take it without sending it to a lab intell I started looking at chemistry of the minerals so that I could identified the minerals that I found in abundance
 
So I would like to say that I fell berry blessed to find this page I have Ben prospecting close to 40 yeare an study's geology learning an searching the mouton crreeks studying busting every kind of rock an studying on it through a 300x lend running the different field tests to track it to a mineral class close as I can take it without sending it to a lab intell I started looking at chemistry of the minerals so that I could identified the minerals that I found in abundance
Welcome to the site.
Check this thread out.

https://goldrefiningforum.com/threads/goldbug-university-ore-photos-tips-hints-etc.6212/
This is a thread that I started with my old profile and have continued to add to with this one.

It was created to help all who have an interest in prospecting and mining.

Enjoy.
 
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