Conglomerate gold

Just wondered if anyone has had much experience with conglomerate gold. I found a patch in some conglomerate country a while back and found it very hard to prospect. By that I mean you're looking for conglomerate or wash from conglomerate, it seems to be anywhere, rather than looking for a good looking for a classic shed from a reef.

There are small dabs of conglomerate around and the country hasn't been worked that well, much at all I think. There is one patch that has been worked by others and mine which is about a km away which hasn't been worked. There's no old timers rubbish.

I found a 52 grammer, on the surface, on top of a hill. Ground looked awesome. Breakaway on one side, 10m from the bit. The hill was basically flat topped, gently sloping away from the breakaway, with heaps of traps and hardly any dirt. Based on the first bit just laying there it should have been covered with slugs - chained it for one 2 grammer about 50m away. My mate found a run off the breakaway side of the hill, about 50 m from where I found the big bit. We got about 2.5 ounces from that run.

The gold from my hill was definitely conglomerate as is the gold from the other patch - it all looks same shape, many water worn bits 2-5 grams. My patch is downstream from the other and we thought for a while that they may be part of a one larger patch, but interesting thing is that when you put the gold from each into two separate piles, they are a distinctly different colour.

Anyway, just wonder if anyone else has any insights they may want to share. I would appreciate your thoughts. Cheers

I couldn't work out how to insert a photo. It took me a while but think I have managed to make a link to a photo of the gold. The piles at bottom left and bottom right are from the two conglomerate patches - you can see the similar shapes but difference in colour. Must have different origins? The biggest bit on the left is the 53 grammer that was sitting on the surface.

Like I said, any ideas on how to read the country?, what to look for?. I know what good quartz looks like but what does 'good' conglomerate look like?

Cheers

I can't help with your question, Stingray ... but I just wanted to say WOW!! Congratulations on your find

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Thanks for the compliments Kate, we were very pleased to say the least. Funny thing was, we had a friend with us who had flown in from interstate to spend a week with us. She had never detected before so we suggested she just walk with us and watch and listen for a little while. Well, she came with me and within minutes I got a faint signal, explained the sound to her and dug up a bit straight away. Then it was pretty much one after another for a couple of days. Unfortunately she now thinks that is how it is all the time! If only!

Stingray

Hahahahahaha!! Just love that story .... can I be your best friend next time, please? ... LOLOLOLOL

Hi Fencejumper, thanks for your thoughts. I must admit I can't recall seeing a difference in colour down slope, but it does make sense. To tell the truth, the main reason I noticed it was because I had just washed the gold and put all the gold from four different spots into the pan for a photo before weighing and doing the divi up. As you would know it is quite usual to get different coloured gold from different areas and even from little patches in the same area, or even in the same patch come to think of it. I can see how that could be when you have individual leaders breaking down and hence each little parcel of nuggets may have a different copper or silver content and hence different colour. How this can happen in conglomerate is not as clear to me.

I tend to think of conglomerate as an old river bed that has turned to stone. Hence, I would have thought the river wash would be relatively well mixed with maybe a number of leaders or reefs contributing gold. In other words a relatively homogenous gold makeup. Perhaps some of the guys who chase river gold can tell me if they see patches of different gold in the one river?

I am now starting to think it may have something to do with the conglomerate matrix. It must have gone through some pretty serious stuff to go from river bed to rock and then out again. Maybe it gets a colouring or signature from the matrix? I guess i could try and cut a nugget from each patch and look inside - but I would prefer not to! Are there any Geos out there who have any ideas?

Anyway, thanks for contributing.

Stingray

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H Fencejumper, looking at the gold again I am pretty sure the colour is due to impurities rather than a stain. One lot looks like 'nice' relatively pure gold, the other lot has a slightly greener tinge - not sure what impurity causes that. Cheers

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Cheers - by the way, I just found out what causes the green colour on another section of the forum, koeh posted this handy link - looks like the green gold has about 15% silver. But hey, still looks and feels like gold, and as you say fencejumper drop in some acid for a while and they look all bright and shiny! What I do, and its probably a big no-no, is to just put the nuggets in a plastic jar with a little water and a good dob of detergent, and shake the crap out of them for a while. To me its just like they have been bumping around the bottom of a creek full of gold for a few thousand years - except all sped up to a few minutes!


http://en.wikipedia.org/wiki/File:Ag-Au-Cu-colours-english.svg

G'day Stingray.

The more silver melted or diluted in with gold,the more brighter the lustre of your gold will be.Pure or close to pure gold will display deep rich brassy looking color.It is the small percentage of copper mixed in with the silver that when combined in with the gold,gives the gold its greenish tarnish look,not the pure silver.Just like any gold found in its natural state,will contain a percentage of impurities the greatest proportion of impurity being silver.So does natural silver contain a small percentage of impurity in the form of copper.

Cheers kon61.

A lot has changed since I posted this back in 2012. No one knew much about conglomerate hosted gold and it wasn't on the radar back then - but it is now after the 'discoveries' by Novo, Artemis etc.. I should have pegged that spot eh?!

Yep!! I found some gold in Clermont Qld recently in a conglomerate looking rock. Three little nuggets inside separate rocks that I busted up - and out they popped.