[HN Gopher] Why gold loves arsenic (2021)
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Why gold loves arsenic (2021)
Author : DoreenMichele
Score : 46 points
Date : 2025-02-08 03:26 UTC (19 hours ago)
(HTM) web link (www.mining.com)
(TXT) w3m dump (www.mining.com)
| OutOfHere wrote:
| So what you are saying is that fool's gold isn't totally foolish.
| memorydial wrote:
| 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!
| labster wrote:
| With this sympathy between gold and arsenic discovered, we're one
| step closer to the philosopher's stone.
| Terr_ wrote:
| Thales of Miletus already made one, but it turned out to just
| be water.
| fjjjrjj wrote:
| It loves mercury too which is also toxic. Interesting.
| ggm wrote:
| But mercury-gold amalgam, maybe different chemistry at play?
| adrian_b wrote:
| 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 wrote:
| 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).
| zdragnar wrote:
| Mercury loves lots of metals. NileRed has some fantastic videos
| playing around with the stuff on YouTube
| refurb wrote:
| It also loves cyanide. Which is why it's used to leach gold in
| mining.
| ggm wrote:
| 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 wrote:
| Not everywhere, just everywhere the sun shines.
| nobodyandproud wrote:
| TMI
| kazinator wrote:
| If you have lots of gold, have your food tested for arsenic.
| zaik wrote:
| Or don't put gold in your food?
| amelius wrote:
| Probably born with a golden spoon ;)
| kazinator wrote:
| Speaking of which, if you were born with a golden spoon,
| would you be eating Zoodles? Dumbest classic commercial
| ever.
| flashfaffe2 wrote:
| 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 wrote:
| 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].
|
| [0]
| https://en.wikipedia.org/wiki/Synthesis_of_precious_metals#G...
| memorydial wrote:
| 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 wrote:
| 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 wrote:
| 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.
| gruturo wrote:
| 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 wrote:
| 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 wrote:
| 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?
| metalman wrote:
| 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...
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