Why is Aus gold so orange? Is it the Iron?

[MrGoldylocks]

Compared to NZ which is classic gold/yellow, Aus gold is orange. I do prefer the typical yellow gold, but love the orangey gold for something unique. When smelted to bars does it stay orange or does that remove the iron content or whatever causes the tinge?

 

[mbasko]

My Australian gold is well ummm...... it's golden yellow not orange?
I've seen some Australian gold being lighter or darker (due to content of other metals like silver, copper etc.) & some stained red/brown/black with iron + other oxides but on the whole Australian gold is the classic golden yellow too IMO? :goldnugget:

 

[Gimp]

Depends if it came out of a burn or creek. No iron content, colour and purity vary widely, it's a bug place bro.

 

[MrGoldylocks]

Nuggets come in some really odd shapes too which is cool about Aus gold.

Yes perhaps impurities. It definitely has a different look and shade to it imo than US gold etc. Maybe its the jagged leafy shapes of some nuggets that just look that way on youtube. When I find another youtube vid of what I mean I will post it.

Aus gold in the red earth must have been hard to spot in the day by eye, it just looks like red rock until cleaned, which I imagine is a very enjoyable process? Seeing the gold coming to shine.

 

[Deepseeker]

The gold I found with my uncle in Blackwood as a kid, was yellowish with an almost slight greenish quality to it if that makes sense? I always assumed that it had some copper in it? I remember reading about some gold that Reg Wilson found once (I think it may have included the Orange Roughie Nugget too?) that was a very reddish orange, that had something to do with either Ironstone or the type of soil it was found in.

One thing that sticks in my mind to this day (and hurts too if I think about it long enough!) is something I once found in Dunolly near Milkmaid gully on one of my first ever trips out with the 5000 running a large SEF coil.
It was a smooth chunk of something about the size of a slightly flattened cherry, that I dug out of the ground. It set my detector off before I dug it up, but when I got it out of the ground it was black. It was incredibly heavy for it's size, but when I looked at it closely it just looked like a smooth black rock.
Waved it over the coil again and it went off again, a loud definite signal. Bounced it up and down in my hand, and once again marvelled at its apparent disproportional heavy weight for its size.
Eventually thinking that it couldn't possibly be gold because it was black I threw it away. It wasn't until I read something some weeks later that I came across mention of gold that had been found at times just up the road in Moliagul that was black, caused by from memory a Manganese oxide coating. I keep anything now that I find that intrigues me or I can't explain. Was it? Wasn't it? Who knows? But it still eats me :| I may be the only D'Head on here who has actually thrown away a nugget :awful:

 

[diggit]

The gold I found with my uncle in Blackwood as a kid, was yellowish with an almost slight greenish quality to it if that makes sense? I always assumed that it had some copper in it? I remember reading about some gold that Reg Wilson found once (I think it may have included the Orange Roughie Nugget too?) that was a very reddish orange, that had something to do with either Ironstone or the type of soil it was found in.

One thing that sticks in my mind to this day (and hurts too if I think about it long enough!) is something I once found in Dunolly near Milkmaid gully on one of my first ever trips out with the 5000 running a large SEF coil.
It was a smooth chunk of something about the size of a slightly flattened cherry, that I dug out of the ground. It set my detector off before I dug it up, but when I got it out of the ground it was black. It was incredibly heavy for it's size, but when I looked at it closely it just looked like a smooth black rock.
Waved it over the coil again and it went off again, a loud definite signal. Bounced it up and down in my hand, and once again marvelled at its apparent disproportional heavy weight for its size.
Eventually thinking that it couldn't possibly be gold because it was black I threw it away. It wasn't until I read something some weeks later that I came across mention of gold that had been found at times just up the road in Moliagul that was black, caused by from memory a Manganese oxide coating. I keep anything now that I find that intrigues me or I can't explain. Was it? Wasn't it? Who knows? But it still eats me :| I may be the only D'Head on here who has actually thrown away a nugget :awful:

No,you're definitely not.

 

[BigWave]

generally Copper, but often after ironstone has been removed through etching, then so has surface copper, so looks golden again.

 

[MrGoldylocks]

thanks bigwave, thats exactly the colour i see. i know everyone is prob use to it. but when i see it just washed, not actually cleaned, some nugs look slightly copperish in colour to me vs river gold in nz which is yellow straight from the pan.

Diggit as long as you keep more nugs than you chuck away you are ahead cobba

 

[jethro]

arty:

Eventually thinking that it couldn't possibly be gold because it was black I threw it away. It wasn't until I read something some weeks later that I came across mention of gold that had been found at times just up the road in Moliagul that was black, caused by from memory a Manganese oxide coating. I keep anything now that I find that intrigues me or I can't explain. Was it? Wasn't it? Who knows? But it still eats me :| I may be the only D'Head on here who has actually thrown away a nugget :awful:

Ya dont remember the area where you threw it away by chance. Lots of black coated gold nuggets get found down around Heathcote too.

 

[Guest]

G'day

Lighter or darker coloured gold is generally due to having a higher content of either copper or silver, both of which are closely associated with gold, but also as said by Deepseeker some nuggets can be iron stained or coated with a black manganese oxide, or can even stained by some other iron oxides in the ground, the coatings are generally easy to remove with an acid bath, but unless you are aware that nuggets can come out of the ground this way in some places then it would be easy to think that it was just some chunk of steel or lead and thrown away.

My first ever nugget that I still have to this day was completely coated in a white calcrete type coating, when I picked it up I was not sure that is was gold and as I wasn't sure so I just pocketed it to have a better look at it later, the second swing over the same spot near the base of some old mine workings produced a rusty wood screw so I wasn't convinced, later in camp I used my knife to scratch the edge of it and instantly saw the gold, been hooked ever since.

I have also encountered a spot where I found many black nuggets, heavy ironstone ground and very volcanic looking rock, the first one I found I was in doubt that it even was a nugget, I tried to clean it a bit to see if it was gold and stuck it in my mouth and it tasted really bad, so I don't do that anymore, ( and this is a very bad thing to do as it can also make you very sick ) but the weight convinced me it was gold so I kept it, I found lots more and once cleaned in an acid bath the nuggets were bright and very smooth.

Many people have also thrown specimen nuggets away as well, as some unless they have visible gold can appear just like a hot rock, probably did that myself in the early days, what I do now is put it on a flat rock and give it a belt with the flat end of my pick, most hot rocks if they are light will just disintegrate, but if they are heavy and more solid I just pocket them and have a better look at them later when in camp, but I never throw them away until I am sure there's no gold in it as I have found gold in all sorts of stone from quartz, ironstone, brown rock and everything in between, and many of these rocks can also be very stained with oxides as well so they are always worth investigating just in case.

cheers

stayyerAU

 

[mbasko]

The gold I found with my uncle in Blackwood as a kid, was yellowish with an almost slight greenish quality to it if that makes sense? I always assumed that it had some copper in it? I remember reading about some gold that Reg Wilson found once (I think it may have included the Orange Roughie Nugget too?) that was a very reddish orange, that had something to do with either Ironstone or the type of soil it was found in.

One thing that sticks in my mind to this day (and hurts too if I think about it long enough!) is something I once found in Dunolly near Milkmaid gully on one of my first ever trips out with the 5000 running a large SEF coil.
It was a smooth chunk of something about the size of a slightly flattened cherry, that I dug out of the ground. It set my detector off before I dug it up, but when I got it out of the ground it was black. It was incredibly heavy for it's size, but when I looked at it closely it just looked like a smooth black rock.

I believe the Orange Roughy was so named because of it's resemblance to the fish not it's colour - Reg might correct me. Here's a pic of it with the bloke that falsely claimed to have found it in the USA.

Looks pretty golden yellow to me.
I think the OP has been watching YouTube vids from WA or other localities with the in situ staining on them from the ground.

Have seen examples of black coated nuggets from Tambaroora NSW too.
They were still golden yellow under the coating.

 

[hAyyoUinAU]

My gold and most Australian gold is known for being some of the most pure in the world. Buttery yellow.
If gold is a orange/yellow that would indicate prob some copper content as said above.
If gold is white/yellow that would indicate some silver present.

But in truth, Australia gold is known as buttery yellow. Pure and delicious to eat.

 

[user 4386]

The colour of the mineral "gold" (not the gold in that mineral) varies from place to place in Australia, the same as it varies from place to place in other countries. It can be coatings or alloys, and because of this can be quite different in colour in different places. For example, it can vary from less than 50% gold in the "gold" to more than 99.7% in Victoria (the rest being silver as just one example).

 

[Deepseeker]

I've heard it referred to as Electrum as well. Is that only once it gets to a certain percentage of Silver though? And, is that what the jewellery industry calls White Gold?

 

[user 4386]

I've heard it referred to as Electrum as well. Is that only once it gets to a certain percentage of Silver though? And, is that what the jewellery industry calls White Gold?

It does not seem to be rigidly defined, but would usually contain 20% or more silver (although I have seen 50% used in some definitions). "White gold is an alloy of gold and at least one white metal (usually nickel, silver, or palladium). Like yellow gold, the purity of white gold is given in karats. White gold's properties vary depending on the metals used and their proportions". Palladium is often used (it is chemically inert like gold).