# Strange black ore



## urbanminer (Nov 8, 2012)

Found an old test pit in NM that had a vein of this black ore running through the middle of it. It is non-magnetic, has a black streak and does not seem to have a significant amount of weight for it's size. I plan on having an assay done here in the near future, but appreciate any of your thoughts.

Marc


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## butcher (Nov 8, 2012)

Looks just like a rock to me :lol: 

http://www.scribd.com/doc/15247849/You-Can-Smelt-Too


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## Platdigger (Nov 8, 2012)

Oh, but such a pretty one.


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## urbanminer (Nov 8, 2012)

Here's another pic of a different rock. I couldn't figure out how to do more than 1 pic per post. This one doesn't have the formations as the other, but seems to be more solid.


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## g_axelsson (Nov 9, 2012)

Just a guess... a weathered sulphide vein where pyrite has turned into iron oxide and hydroxides (ie rust). A lot of the original material has been weathered out and left the vein with this hollow and irregular material. The black streaks are from remnants of sulphides still embedded in the more massive parts.

I would suspect that deeper down (depending on the local geology) you would find the massive vein with fresh material. That could actually hold less of values as the weathering process could concentrate the values in the weathered part. I've heard about some gold mines in Australia (owned by Boliden) that saw that effect.

If I was mining (which I'm not) I would get an assay on that material but I would be careful to not cherry pick the best part and think that all would be of the same quality.

Let us know what the final assay reports.

/Göran


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## donnybrook (Nov 9, 2012)

If you could acquire more of the material try and locate someone with a hammer mill. Place the material on a tarp and start to pull up the corners one at a time. Repeat several times to get an even mix. You will finish up with a cone. From each quarter take a sample. Send it off for assay.
donnybrook


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## urbanminer (Nov 9, 2012)

I plan on getting an assay next week. Unfortunately they are closed this week, I beleive for a family emergency. As soon as I get the results I'll post the findings. Untill then, here's a close-up of some of the formations.


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## Labman (Nov 10, 2012)

My guess: Manganese and or lead. Colorado gold ores are often gray, especially in Cripple Creek area.


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## nh6886 (Nov 20, 2012)

Just wondering what your ore turned out to be?


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## urbanminer (Nov 27, 2012)

I should have posted the results earlier, but the holiday threw me off. Here are the results of the EDXRF. It did detect silver, but no gold. He did mention that the XRF has a hard time quantifying gold. The results from the fire assay didn't copy/paste well. It did show 2.89 oz/T silver and .33 oz/T gold. I didn't expect gold in the sample, so it's a nice suprise. I definately need to do more sampling and uncover more of the vein to see if I should proceed further.

Date: 11-15-12 
Sample ID	Al	Si	SiO2	P	K	S	Fe	Ca	Ti 
%	%	%	%	%	%	%	%	% 
MJ-1	<0.1 18.3 39.1 0.1 <0.1	0.94 12.1	1.1 <0.1 
V	Cr Ni	Cu	Zn	As	Ba	Pb	Mo	Sr	
ppm	ppm	ppm	ppm	ppm	ppm	ppm	ppm	ppm	ppm	ppm	
MJ-1	31 <20 <20 <20 861 19,540 9,600 34,490 1,150 61 
Zr Sn	Y	Mn 
ppm ppm	ppm	ppm	ppm	ppm	ppm	ppm	ppm 
MJ-1	24 91 55 22,700 
ppm=ug/g Method: EDXRF Calibrated	SQ 
ug/g x 0.0001=Wt% Similar Standards 
ND= No Detection


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## urbanminer (Nov 27, 2012)

That didn't copy well either! :shock: It copied well on the reply, but.... Sorry, I'll try to clean this up after work.


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## g_axelsson (Nov 27, 2012)

Let me fix that for you...



urbanminer said:


> ```
> Date: 11-15-12
> Sample ID   Al     Si     SiO2   P      K      S      Fe     Ca     Ti
> %      %      %      %      %      %      %      %      %
> ...



A lot of quartz and iron.... I guess that some of the missing mass is O and OH in the rust.
Some Zn, Ba, As and Pb. It sounds like an old hydrothermal vein that's been weathered.
I'm a bit surprised by the low level of S and Al.

Thanks for sharing the results. 
/Göran


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## shaftsinkerawc (Nov 27, 2012)

Can you try the Fire Assay results so they can be compared to the XRF.


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## Labman (Nov 27, 2012)

My suggestion is to fine grind, sluice, adjust your concentration efforts to achieve 150 lbs of concentrate per metric ton. Open air roast, then smelt with carbon to achieve 75 lbs of hard lead (about 50%). Scorify and slag off copper oxides, etc. then use the Parkes Process. Remove the zinc with 10% sulfuric acid and then switch to 50/50 nitric acid to dissolve silver. Cupel the remainder to get your gold. I know this is an over simplification, but you can get the details on line if you search.


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## urbanminer (Nov 28, 2012)

Thanks g_axelsson. Don't know what you did, but it worked.

I'll try the fire assay results, but on another forum it really copied weird.



Fire Assay

Date: 11-16-12
Assay Type: PbO Crucible Assay Ton: 1/2 A.T. (14.58 g)


Sample ID WT Wt oz/T oz/T oz/T g/T
g Precious Precious Au Ag Precious
Metals Metals Metals 
mg g/T 
JM-1	14.6349	1.60	3.19	0.33	2.86	10.3	

Dore’ Bead Color-Silver 


Calculations
ppm=µg/g x 0.0292=oz/T 
mg x 1000 = µg
oz/T x 31.1 = g/T

As far as working this ore, it's in another state. I do beleive more samples from different sections of the vein come first. Did I submit a rich/poor sample? Was this the richest/poorest part on the vein? How extensive is the vein? This area is also in a very green county. The BLM land is next to a state park. Can a NOI/POO even be obtained reasonably?

I don't want to sound negative, but I do need to dot my I's and cross my T's if I choose to work this area on this level. Comments are appreciated.


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