Ore identification please help

[Reno Chris]

No. 10 is a chunk of copper ore from Nevada. The sulfide mineral here is tetrahedrite, a sulfide of copper and antimony. No gold or silver.

 

[BlackLabel]

Hi Chris,

Many thanks for your answers!
I had two hits only (1+6).

I‘d love to do such a quiz again!

Best regards from Germany!

 

[orvi]

No. 7 is molybdenum ore from Nevada. Its nice and sparkly with moly sulfides and looks good, but has no gold or silver.

This is very nice example of the point we had. Some sorts of hematite look completely analogous to this. Also pyrite, I have seen similarly structured antimony/tetrahedrite ore (very strange)... Some had gold, some trace gold, some no gold, some had silver, some were completely PM free.

With knowledge of local geology and known location of sample, it may well be possible to identify the types of minerals in it - but just with optical similarity. If you are mining malachite, this obviously isn´t very problematic. But if you are searching for invisible gold in porphyry/Carlin type deposit, or even for gold locked in sulfides/arsenopyrite etc, you must be very well prepared and experienced. Cannot say it from scratch, with certainty. Espetially with somebody´s money at stake.

We had multiple times samples of tetrahedrite from one location - all looked the same, solid microcrystalline stuff, shiny... Nothing to distinguish between them, all veins were approximately in 100 m radius in the same level of mine... Yet one assayed 10g/t Ag, second 25g/t Ag and third 1,5 % Ag
Content of the antimony varied from 0 to 3% in them, also arsenic had similar trends.
No means of educated guess could resolve it, aside XRF or proper assay.

Overall, very nice samples, some very significant ones

 

[Reno Chris]

No means of educated guess could resolve it, aside XRF or proper assay.

And that was my original point. Lots of gold ore has been ignored by people - even knowledgeable ones - who have an idea in their heads as to what good quality gold ore looks like. They are right most of the time, but the times they are wrong can be costly. Its important to have that idea of what ore should look like, but its also important to keep an open mind and be willing to think outside the box.

 

[gldfever87]

Its so wonderful to have found someone as knowledgeable as you are! Just to confirm your extensive expertise, I have attached 10 pictures of some rock. Can you well me which of these have significant gold? I actually know about all 10, so I know the correct answers from testing and assaying, but I am sure you will get 100% correct! Please let us know your determinations. Just a hint, there is no visible gold in any of them, though some are very rich in gold.

O just recently started processing granite ore of all types, PGMS, Iron ore with gold, Platinum, and iridium ore, which I think maybe it's a meteorite..

 

[gldfever87]

And silver. Very pure.

 

[Reno Chris]

gldfever87 - Please read my previous posts on this thread.
The whole point of my response to this thread was that you cannot just look at rocks and give an accurate "Eyeball assay".
If photos were all that was necessary, there would be no need for any assay labs, or testing equipment like the XRF.
Yet there are assay labs and testing equipment. This will prove to you that blurry cell phone shots cannot really tell you much of anything.
I get a number of folks everyday who want me to look at their rocks and tell them that they have "Struck it rich". Sorry, I do not offer a photo ID service.
Here is what I suggest:
1) Crush the rocks down to sand size. 2) Carefully pan the sand. 3) If you do get any gold, get an assay test done by a lab to confirm.

 

[Reno Chris]

Sample #1. The samples of hematite enriched material similar to this that I have assayer has never been any less than 1/5 of an oz per ton gold.
#'s 6, 7 & 10 are my other choices for most likely material.
Sample #7 would be suspect for silver and possibly pgm's.
#'s 2, 3 & 5 would be secondary choices with expectations of silver being dominant.
There, I answered your retort. Let's see how I scored.

OK, Rick I am seeing your Amazing Skill Set did not stand up to the test.
No. 1 is gold ore, but only 2 grams a ton, so less than your "never less than 1/5th of a ton"
6 is gold ore, but 7 and 10 have no gold.
7 is moly ore, with no silver or PGMs.
2, 3 and 5 are rich gold ores, all with very little silver.
I would say that you did not confirm that you could look at ores and just tell if they were good or not.

 

[gldfever87]

OK, Rick I am seeing your Amazing Skill Set did not stand up to the test.
No. 1 is gold ore, but only 2 grams a ton, so less than your "never less than 1/5th of a ton"
6 is gold ore, but 7 and 10 have no gold.
7 is moly ore, with no silver or PGMs.
2, 3 and 5 are rich gold ores, all with very little silver.
I would say that you did not confirm that you could look at ores and just tell if they were good or not.

Did not mean to come off as rude. I do know the difference in certain ores and am always learning. Yes I've done acid test fire assay and oxidation.

 

[Briancline]

Just had a brilliant idea. Lets let people post pictures of their metallic alloys. Then we can have a $ 5-10 pool to guess which one has gold or silver, or whatever.

Can you help with what this is?

 

[BlackLabel]

Can you help with what this is?

I would say calcite on limonite.

 

[PeterM]

No idea what it is? It matters not. Does it contain value? Probably not. Good looking rocks never told me anything. Learn to Fire Assay, is the first step. Wet Chemical analysis is the second step.

 

[goldshark]

At least put a couple of drops of white vinegar or HCL on it to see if it fizzes. Fizzy = Calcite, no fizz, more than likely quartz. If you can't assay it yourself, then farm it to those who can. If it is a single piece of float, put it in the rock garden. If you found a seam of it and interested to see if it has any value, hire a professional exploration geologist. Orrrr, spend the rest of your life hooked on mining, processing, permitting, refining, etc..

 

[Soar2c]

At least put a couple of drops of white vinegar or HCL on it to see if it fizzes. Fizzy = Calcite, no fizz, more than likely quartz. If you can't assay it yourself, then farm it to those who can. If it is a single piece of float, put it in the rock garden. If you found a seam of it and interested to see if it has any value, hire a professional exploration geologist. Orrrr, spend the rest of your life hooked on mining, processing, permitting, refining, etc..

Why would you hire a prof exploration geologist, if, a seam was found and curious if it contains value?

I'm not following why this is what your thoughts are as the only 2 suggestions you mention for "wanting to know if a vein had value". Please explain for those of us who are lost and relatively new to this.

 

[goldshark]

P.S., welcome to the forum. A pretty good, tough crowd though. They tell it like it is.

Why would you hire a prof exploration geologist, if, a seam was found and curious if it contains value?

I'm not following why this is what your thoughts are as the only 2 suggestions you mention for "wanting to know if a vein had value". Please explain for those of us who are lost and relatively new to this.

If you value your time, you will take my advice. Mining a deposit is a very expensive proposition. You still haven't answered the basic question as to the sample you submitted being either an in place seam, or a single piece of rock laying on the ground that you found. You obviously haven't been on the forum long enough to read some of the comments on rocks submitted via a picture. Please read them. A rock picture can in no shape or form be analyzed by a picture. It requires chemical analysis. No one on here ,with any credibility, will give you an answer, other than "looks like a rock". This is because we mean business when it comes to the subject of refining, being the initial concentration of ores, to the final refinement into purified elements. It is actually offensive to do what you ask, to this forum. Please read a simple book on geology, minerals, assaying, etc.. We cannot solve the worlds problems, if they refuse to help themselves. If you don't help yourself, then pay the guy/gal who can give you the answers to your questions. That is what I mean by hire a professional geologist if you want answers now. You obviously think you may have something of value, or you wouldn't ask about a rock composition on a Gold Refining Forum format. Almost all members on this forum have answered questions about a rock picture, much to their frustration. I think this is the last time I will comment on another "rock" picture. It sucks too much energy out of a forum designed by professionals for beginning to advanced refining, not geology 101. You may be lost, but to find yourself, YOU must learn to help yourself, become the sponge of knowledge by reading and experimenting about the subject. When you have a question about a certain procedure, feel free to ask here, but please read the many valuable posts on the various threads that abound on this forum, to see if it has already been discussed. It probably has, as this is a very knowledgable group covering just about every facet of the industry.