Having panned for gold in Gympie I was convinced I'd come home with a lot of pyrites and now 30 years later I feel I need to revisit that tiny jar of yellow dust.
(Got a killer dose of sunburn just above the bum crack bending over in the stream with my pan, a reminder sunscreen has to go EVERYWHERE.)
stavros 21 days ago [-]
Not everywhere, just everywhere the sun shines.
nobodyandproud 21 days ago [-]
TMI
kcplate 20 days ago [-]
I found it a helpful tip quite honestly.
memorydial 21 days ago [-]
Fascinating read! So if arsenic helps gold concentrate in deposits, does this mean arsenic-rich environments are better places to prospect? Or is it more about how existing deposits form rather than finding new ones?
fjjjrjj 21 days ago [-]
It loves mercury too which is also toxic. Interesting.
zdragnar 21 days ago [-]
Mercury loves lots of metals. NileRed has some fantastic videos playing around with the stuff on YouTube
ggm 21 days ago [-]
But mercury-gold amalgam, maybe different chemistry at play?
adrian_b 21 days ago [-]
Metallic gold alloys easily with mercury, so it can be dissolved by mercury.
It also alloys easily, i.e. it is dissolved, with other liquid metals, e.g. silver, copper, indium etc., but that is less obvious than with mercury, because those metals must first be heated to great temperatures, to become liquid, before dissolving gold.
The relation with arsenic is different. It is an affinity between ionic gold and arsenic, not between metallic gold and arsenic.
The gold ions are very big, among the biggest metallic ions. Because of that, the gold ions have great affinity only for some big anions (negative ions), i.e. for the ions of arsenic or of tellurium, which have approximately the same size.
This is in contrast with the smaller ions of silver and copper, which have great affinity with the smaller anions of sulfur.
It is well known that the gold ions have the greatest affinity for the anions of the size of arsenic and tellurium. Tellurium has an even greater affinity for gold than arsenic, but tellurium is extremely rare at the surface of the Earth. Due to the rarity of tellurium, even if minerals with gold and tellurium are well known they are less frequently found than those were gold is associated with arsenic.
While the maximal affinity of gold with tellurium and arsenic has been well known, this research has elucidated details of the mechanism how this creates arsenical minerals rich in gold, which may help in the prospection for such minerals.
Because gold is normally much more scarce in the environment than arsenic and than other metals with which arsenic combines easily, the minerals with arsenic and gold are seldom straightforward combinations of arsenic and gold, but as explained in the article, gold infiltrates arsenides of other metals (usually of iron, whose arsenide is the most abundant).
pfdietz 21 days ago [-]
In Kalgoorlie, Australia, gold telluride was not recognized as such, but was instead misidentified as pyrite and was used as a paving material. The streets were literally paved with gold (since recovered).
refurb 21 days ago [-]
It also loves cyanide. Which is why it's used to leach gold in mining.
metalman 21 days ago [-]
quick search on "arsenic in water" yields endless
official governmental and other notices all over the world, so there does not apear to be a direct
asosiation between (recoverable) gold and arsenic
and that it is so prevelant that some humans have adapted and pass arsenic.
https://www.smithsonianmag.com/smart-news/centuries-poison-l...
OutOfHere 21 days ago [-]
So what you are saying is that fool's gold isn't totally foolish.
memorydial 21 days ago [-]
Right? Turns out fool’s gold has a bit of wisdom after all. It won’t make you rich, but in the right conditions, it can help concentrate the real stuff!
kazinator 21 days ago [-]
If you have lots of gold, have your food tested for arsenic.
zaik 21 days ago [-]
Or don't put gold in your food?
amelius 21 days ago [-]
Probably born with a golden spoon ;)
kazinator 21 days ago [-]
Speaking of which, if you were born with a golden spoon, would you be eating Zoodles? Dumbest classic commercial ever.
labster 21 days ago [-]
With this sympathy between gold and arsenic discovered, we’re one step closer to the philosopher’s stone.
Terr_ 21 days ago [-]
Thales of Miletus already made one, but it turned out to just be water.
flashfaffe2 21 days ago [-]
Genuine question for an outsider: would this imply that gold can be created? My memories from the last chemistry class I had, I clearly remember my teacher demonstrating philosopher stone ( aka changing materials in gold ) was feasible.
somebodynew 21 days ago [-]
This article is about arsenic minerals acting like a sponge that holds and concentrates gold from the surrounding environment that it comes in contact with. It isn't creating new atoms of gold.
Gold can be created through an unrelated process of nuclear transmutation, but it's impractically expensive [0].
Gold is a chemical element, not an alloy or any kind of mixture of other things - so no, chemical reactions won't help you get gold.
Nuclear reactions WILL produce gold - in many ways actually (none profitable afaik):
- throw a neutron or 2 at neighboring elements, ensure they have the right energy for the cross section, hopefully with neutron capture and beta decay you get some gold (maybe the stable Au197 version, maybe a violently radioactive isotope though, I wouldn't wear a ring made of that. And it will eventually stop being gold when it decays). Oh an immense amount of radioactive byproducts. And the starting elements are often more expensive than gold itself.
- Fuse 2 lighter elements with just the right weights, you may get gold. But creating elements above iron is energy-negative so your fusion reaction will immediately die unless you can sustain it. All the gold we found on the planet was created during supernovas IIRC.
- Fission something heavier and hope that gold is one of the pieces you're left with.
- Start with an unstable isotope of Thallium, Bismuth, etc and hope for a few alpha decays to line up and get you gold.
There are actually quite a few paths.... and ALL the gold you'll ever see, whether artificial or "natural", was created with one or another (but most really is from supernovas). Remember, we started with only the building blocks in the big bang, mostly Hydrogen.
BobaFloutist 21 days ago [-]
Yeah it's always tickled me that we probably do have the technology to turn lead to gold, it would just be at an incredible loss. Almost fable-like that (one aspect of) what alchemists dedicated their whole lives to chasing is actually possible, just not actually worth it.
It's like if the federal government allowed you to print your own money but only if it was ones and it turned out that it cost $100/bill to do it properly.
memorydial 21 days ago [-]
Nope, this doesn’t create gold, just helps existing gold accumulate in certain conditions. Actual gold creation requires nuclear reactions, which are technically possible but not practical.
pfdietz 21 days ago [-]
Maybe not as impractical as you think.
Gold could be made by neutron capture on Hg-196. This is a rare isotope, so doing so would require two things: cheap neutrons, and a cheap way to enrich that isotope.
Helion's FRC scheme could provide the first if operated on DD (even if just at engineering breakeven). As for the latter, there's a scheme that's been proposed for mercury isotope separation that exploits the change in magnetic moment of mercury atoms when they are optically excited. This would use radiation from a mercury lamp that itself uses isotopically separated mercury to produce radiation that would selectively excite just that isotope, and steer the atoms in a beam using a magnetic track.
(This isotope separation technique has been proposed as a way to make fluorescent lights more efficient by reducing UV photon trapping in mercury vapor.)
The world's mercury production is low enough and this isotope rare enough that this wouldn't affect gold prices.
Tuna-Fish 21 days ago [-]
A fun little fact: We now have the ability that alchemists sought for so long (transmuting elements through nuclear reactions), and we are using it to destroy gold, not create it.
The processes involved are so expensive to do that in terms of cost it doesn't really matter what you are using as the source material, and the way gold is very resistant to corrosion is useful for using as a target in experiments.
Rendered at 10:41:08 GMT+0000 (Coordinated Universal Time) with Vercel.
(Got a killer dose of sunburn just above the bum crack bending over in the stream with my pan, a reminder sunscreen has to go EVERYWHERE.)
It also alloys easily, i.e. it is dissolved, with other liquid metals, e.g. silver, copper, indium etc., but that is less obvious than with mercury, because those metals must first be heated to great temperatures, to become liquid, before dissolving gold.
The relation with arsenic is different. It is an affinity between ionic gold and arsenic, not between metallic gold and arsenic.
The gold ions are very big, among the biggest metallic ions. Because of that, the gold ions have great affinity only for some big anions (negative ions), i.e. for the ions of arsenic or of tellurium, which have approximately the same size.
This is in contrast with the smaller ions of silver and copper, which have great affinity with the smaller anions of sulfur.
It is well known that the gold ions have the greatest affinity for the anions of the size of arsenic and tellurium. Tellurium has an even greater affinity for gold than arsenic, but tellurium is extremely rare at the surface of the Earth. Due to the rarity of tellurium, even if minerals with gold and tellurium are well known they are less frequently found than those were gold is associated with arsenic.
While the maximal affinity of gold with tellurium and arsenic has been well known, this research has elucidated details of the mechanism how this creates arsenical minerals rich in gold, which may help in the prospection for such minerals.
Because gold is normally much more scarce in the environment than arsenic and than other metals with which arsenic combines easily, the minerals with arsenic and gold are seldom straightforward combinations of arsenic and gold, but as explained in the article, gold infiltrates arsenides of other metals (usually of iron, whose arsenide is the most abundant).
Gold can be created through an unrelated process of nuclear transmutation, but it's impractically expensive [0].
[0] https://en.wikipedia.org/wiki/Synthesis_of_precious_metals#G...
Nuclear reactions WILL produce gold - in many ways actually (none profitable afaik):
- throw a neutron or 2 at neighboring elements, ensure they have the right energy for the cross section, hopefully with neutron capture and beta decay you get some gold (maybe the stable Au197 version, maybe a violently radioactive isotope though, I wouldn't wear a ring made of that. And it will eventually stop being gold when it decays). Oh an immense amount of radioactive byproducts. And the starting elements are often more expensive than gold itself.
- Fuse 2 lighter elements with just the right weights, you may get gold. But creating elements above iron is energy-negative so your fusion reaction will immediately die unless you can sustain it. All the gold we found on the planet was created during supernovas IIRC.
- Fission something heavier and hope that gold is one of the pieces you're left with.
- Start with an unstable isotope of Thallium, Bismuth, etc and hope for a few alpha decays to line up and get you gold.
There are actually quite a few paths.... and ALL the gold you'll ever see, whether artificial or "natural", was created with one or another (but most really is from supernovas). Remember, we started with only the building blocks in the big bang, mostly Hydrogen.
It's like if the federal government allowed you to print your own money but only if it was ones and it turned out that it cost $100/bill to do it properly.
Gold could be made by neutron capture on Hg-196. This is a rare isotope, so doing so would require two things: cheap neutrons, and a cheap way to enrich that isotope.
Helion's FRC scheme could provide the first if operated on DD (even if just at engineering breakeven). As for the latter, there's a scheme that's been proposed for mercury isotope separation that exploits the change in magnetic moment of mercury atoms when they are optically excited. This would use radiation from a mercury lamp that itself uses isotopically separated mercury to produce radiation that would selectively excite just that isotope, and steer the atoms in a beam using a magnetic track.
(This isotope separation technique has been proposed as a way to make fluorescent lights more efficient by reducing UV photon trapping in mercury vapor.)
The world's mercury production is low enough and this isotope rare enough that this wouldn't affect gold prices.
The processes involved are so expensive to do that in terms of cost it doesn't really matter what you are using as the source material, and the way gold is very resistant to corrosion is useful for using as a target in experiments.