Alunite, kaolin, and silver in otherwise uninteresting area

[Boarteats]

Might not be able to answer, but...

I am checking out a stream. In particular, digging down to clay layer to see if there is any gold hanging out at the sand/clay boundary. Hasn't been terribly interesting. Most of the area at clay layer has been cobble, gravel, etc. Little to no gold. Although, I have found a few lead nuggets. Woohoo.

Recently, however, I starting to find discrete patches that are entirely alunite/kaolinite rock instead of hodgepodge of other rock. Get some silver when panning soil near this layer. Much of the alunite rock has what appears to be silver sulfide on/in it. (Still need to verify this id). Panning material in these areas shows a large amount of black, non-ferromagnetic, heavy mineral (notably heavier than magnetite) and small amount very fine gold. Guessing dark mineral might be silver sulfide as well. Could be something else, of course.

Here is my question. Alunite/kaolinite rock didn't accidentally concentrate in these patches via some random process, so what's going on?

Might these patches of alunite/kaolinite (along with associated silver sulfides) be part of some other interesting geologic formation that can point me to more valuable minerals (e.g. gold)?

Easy question, right?

 

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[Mad Machinist]

What may have happened is the river cut through a vein of it fairly close by. I wouldn't call silver "uninteresting" though. Give me a vein with high enough concentration and I'll go after it. Never know, you just might find another Tombstone or a whole new district.

 

[Gambrinus]

What may have happened is the river cut through a vein of it fairly close by. I wouldn't call silver "uninteresting" though. Give me a vein with high enough concentration and I'll go after it. Never know, you just might find another Tombstone or a whole new district.

This reminded me of when I read about gold miners in Nevada complaining about the blue-black clay type material clogging their rocker box until someone decided to test that muck.
The site came to be known as the Comstock Lode.

 

[Boarteats]

This reminded me of when I read about gold miners in Nevada complaining about the blue-black clay type material clogging their rocker box until someone decided to test that muck.
The site came to be known as the Comstock Lode.

Lol. I would be happily surprised if I discover Comstock Lode amounts of silver! However, I wouldn't bet the farm on it.

 

[Mad Machinist]

Lol. I would be happily surprised if I discover Comstock Lode amounts of silver! However, I wouldn't bet the farm on it.

Anything is possible. They said the geology was all wrong for rare earths in Arizona. Look at the La Paz district. Or maybe Round Top Mountain in Texas.

NOTHING about geology is set in stone. Did I just make a funny?

 

[Boarteats]

Anyone know a test to positively id silver sulfide other than visual inspection and specific gravity? Haven't found much online on this topic.

Edit...
These are types of rocks that I’m pulling from my current dig site. Most of the sparkly bits are pyrite. However, some of it is gold. Was surprised. Assumed that it was all pyrite at first glance. Took a closer look today, crushed a bit and panned.

Probably should just send out for assay at this point.

Only assay companies that I know have a few hundred dollar min. Any suggestions for company with lower or no min per order would be much appreciated.