# Insoluable material (non magnetic black sands)



## Ragnor (May 30, 2017)

I am wondering if anyone can help me on this. I collected some black sand from a creek here in western Washington for testing. I separated off the magnetic sands and placed 4 grams of wet material in a beaker. 
4 grams did not cover the bottom of a 50ml beaker. It's quite heavy.
I added just enough nitric to cover the sands and waited an hour. Nothing happened. I then added an equal part of water. I waited 2 more hours, nothing happened. Then I added about a quarter tsp of table salt. Over the next few minutes the solution turned a light green and still nothing happened. 

I suppose the next step is to boil the sands in aqua regia? 

I tested the solution at each step with stannous chloride and always get a negative reaction.

I really want to know what this material is. someone on another forum suggested REE's 

I'm wondering if anyone has suggestions on what insoluable materials I might want to research that resist acid attack. Yes perhaps I am asking prematurely, maybe the boiling AR will do the trick, but I have my doubts and I think I'll go prospecting today instead of sitting around watching acid boil (or not watching). 

It's just on my mind , so I figured I'd ask.


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## g_axelsson (May 30, 2017)

Sounds like black heavy rocks that doesn't dissolve in aqua regia. Nothing I personally collects.

Göran


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## Ragnor (May 30, 2017)

There are entire populations in Africa enslaved to this day collecting black heavy rocks that no one else collects....


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## galenrog (May 30, 2017)

There are several black and dark colored mineral sands that resist nitric acid. That is true even on the western slopes of the Cascade Mountains. 

I would suggest that you take a look at the Prospecting & Mining section in the forum. There is a sticky at the top with field testing procedures. Essentially the same information I learned 35-40 years ago. I still take copies of various test procedures with me when I do happen to go to old mines and prospects. 

Playing hit and miss, combining unknown materials with acids, in my opinion, is not a plan. Rather, it is foolishness. Please learn how to test your materials.


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