Question Moon Gold

[Craftsman X]

Would gold be present in significant amounts on the moon? If so how would it be located, and mined?
Actually come to think of it wouldn't surface found moon rock give a better return for your money anyway?
Or are there more valuable resources (versus their ease of extraction)
Personally the romantic value alone of a Moon Gold wedding ring for example would increase its value against boring old earth gold??

 

[COLGeek]

The cost of mining operations will make for pretty expensive materials....even if just moon rocks.

 

[Geomartian]

Uranium was found in concentrations of more then 100 ppm in some samples returned by the Apollo astronauts from the Moon. The KREEP component (which Houston refuses to analyze properly) is largely radioactive because of the presence of uranium, not potassium.

With its vacuum and low gravity, the Moon can concentrate heavy elements like uranium in the vaporized material which does not escape the Moon’s gravity well. This mechanism is basically identical to the terrestrial mechanism which concentrates uranium in black shale. Both are driven by the temperatures generated by the impacts of interstellar asteroids.

Uranium appears to be concentrated in vast areas of the Moon’s surface. Uranium mining on the Moon could be feasible within a few decades.

Fissionable materials will be in high demand in space. Because of the Moon’s vacuum, techniques for uranium isotope enrichment could be based on simply heating uranium with solar furnaces or lasers. Large scale isotope separation using time of flight or ballistic separation becomes possible because of the conditions found on the Moon.

Based on the absolute need for fissionable materials (uranium) in space, mining uranium within the gravity well of the Moon is worth the effort.

Gold is not as useful as uranium.

 

[Craftsman X]

Uranium was found in concentrations of more then 100 ppm in some samples returned by the Apollo astronauts from the Moon. The KREEP component (which Houston refuses to analyze properly) is largely radioactive because of the presence of uranium, not potassium.

With its vacuum and low gravity, the Moon can concentrate heavy elements like uranium in the vaporized material which does not escape the Moon’s gravity well. This mechanism is basically identical to the terrestrial mechanism which concentrates uranium in black shale. Both are driven by the temperatures generated by the impacts of interstellar asteroids.

Uranium appears to be concentrated in vast areas of the Moon’s surface. Uranium mining on the Moon could be feasible within a few decades.

Fissionable materials will be in high demand in space. Because of the Moon’s vacuum, techniques for uranium isotope enrichment could be based on simply heating uranium with solar furnaces or lasers. Large scale isotope separation using time of flight or ballistic separation becomes possible because of the conditions found on the Moon.

Based on the absolute need for fissionable materials (uranium) in space, mining uranium within the gravity well of the Moon is worth the effort.

Gold is not as useful as uranium.

Many thanks Geo...
In terms of something like gold though would the geology be similar - to earth- in terms of its deposition/formation?
I realise that there isn't the erosion associated with water or wind that determine the ease of finding it, but would it be found in association with the same minerals and stratigraphy that it would here on earth?
So for instance if you were determined enough(!) what would be the pointers (either geographically or geologically) that you would look for first? … if there are any

 

[Ken Fabian]

I would not expect any decent gold bearing ores on the moon.

Gold ores on Earth - like many other important mineral ores - are mostly formed by hydro-thermal processes; dissolved out of rock (basalts) that contain low concentrations by hot water at high pressure and carried to where conditions cause precipitation of gold sulphides, tellurides and elemental gold. It is strongly associated with tectonic plate boundaries.

Later erosion can deposit the gold within sands and silts and with water movement, the high density tends to result in the gold settling to the bottom - placer deposits.

Such conditions appear to be absent on the moon.

 

[Craftsman X]

I would not expect any decent gold bearing ores on the moon.

Gold ores on Earth - like many other important mineral ores - are mostly formed by hydro-thermal processes; dissolved out of rock (basalts) that contain low concentrations by hot water at high pressure and carried to where conditions cause precipitation of gold sulphides, tellurides and elemental gold. It is strongly associated with tectonic plate boundaries.

Later erosion can deposit the gold within sands and silts and with water movement, the high density tends to result in the gold settling to the bottom - placer deposits.

Such conditions appear to be absent on the moon.

Fascinating - many thanks for the detailed reply

 

[YetAnotherBob]

Current belief is that the Moon was formed from a big splash when a Mars sized planet collided with Earth.

So the Moon has everything that the crust of Earth has. There is more because of asteroid collisions through the ages.

So yes, there is gold on the Moon. But on Earth we have gold deposits that were laid down by bacteria processing the elements that are randomly distributed through the ground. Water flow plays into that.

The Moon has no ground water and no bacteria that we know of. Therefore, no gold veins.

Still, as we process iron, aluminum and silicon we will get by-products. Things like gold, platinum, silver, tin, copper and so forth are all there, and the miners can accumulate these materials over time. Slag can be mined for other minerals, but you will need to have good systems to recover it.

The same is frequently true on Earth. I am aware of some copper mines where they actually pulled out more in dollar amounts in gold than they did in copper. It was less than a twentieth by weight, but in dollar amounts, the gold was sometimes worth more than the copper.

Many asteroids have sizable quantities of rare earth elements. Often more than is commonly found on Earth as a whole. Tracing those rare earths was how Scientists proved that an asteroid killed off the dinosaurs.

But without all those helpful bacteria, it takes a lot of work to get the materials.

So we are more likely to get valuable materials like semi-conductors or high tech alloys than simple gold.

Transport can be cheap from the Moon to the surface of the Earth, but is astronomically expensive from Earth to Moon.

The same problems exist for things like Tritium and iridium or Rhodium as well.

 

[Craftsman X]

Current belief is that the Moon was formed from a big splash when a Mars sized planet collided with Earth.

So the Moon has everything that the crust of Earth has. There is more because of asteroid collisions through the ages.

So yes, there is gold on the Moon. But on Earth we have gold deposits that were laid down by bacteria processing the elements that are randomly distributed through the ground. Water flow plays into that.

The Moon has no ground water and no bacteria that we know of. Therefore, no gold veins.

Still, as we process iron, aluminum and silicon we will get by-products. Things like gold, platinum, silver, tin, copper and so forth are all there, and the miners can accumulate these materials over time. Slag can be mined for other minerals, but you will need to have good systems to recover it.

The same is frequently true on Earth. I am aware of some copper mines where they actually pulled out more in dollar amounts in gold than they did in copper. It was less than a twentieth by weight, but in dollar amounts, the gold was sometimes worth more than the copper.

Many asteroids have sizable quantities of rare earth elements. Often more than is commonly found on Earth as a whole. Tracing those rare earths was how Scientists proved that an asteroid killed off the dinosaurs.

But without all those helpful bacteria, it takes a lot of work to get the materials.

So we are more likely to get valuable materials like semi-conductors or high tech alloys than simple gold.

Transport can be cheap from the Moon to the surface of the Earth, but is astronomically expensive from Earth to Moon.

The same problems exist for things like Tritium and iridium or Rhodium as well.

fantastic, many thanks

 

[Catastrophe]

"So the Moon has everything that the crust of Earth has." My emphasis.

Don't you think gold / uranium heavy whatever would have concentrated towards the centre of the proto-Earth so that the Theia collision would have left the Theia remnants with somewhat less heavies, leaving Earth supplies intact.

To put it simply. Earth retained most of proto-Earth's heavy metals.
Theia remnants plus proto-Earth crust were not enriched in heavy metals.

 

[YetAnotherBob]

"So the Moon has everything that the crust of Earth has." My emphasis.

Don't you think ...

No.
Theia was largely consumed by the then molten Earth. It sank to the core. What was left on the survace and around in Space was largely the same isotopically, according to analysis of the Moon Rocks to the geology we find on Earth today. That's how they arrived at the Theia concept.

"So the Moon has everything that the crust of Earth has." My emphasis.

Don't you think gold / uranium heavy whatever would have concentrated towards the centre of the proto-Earth so that the Theia collision would have left the Theia remnants with somewhat less heavies, leaving Earth supplies intact.

To put it simply. Earth retained most of proto-Earth's heavy metals.
Theia remnants plus proto-Earth crust were not enriched in heavy metals.

I've seen it debated. For the Earth, the answer seems to be a qualified 'Yes, but'.
You are a retired Engineer, so you know what that means, and what it's worth.
There is assumed to be more of the heavier elements as you get deeper down, only we can't go deeper down. The deepest we can recover minerals is from volcanic eruptions, and that's only about twenty miles. The regions that would have more of the more valuable minerals are Thousands of miles down, not tens. Our mining efforts seldom go more than a mile or so down.
So the real answer is that we just don't know. There are educated guesses, but they are only guesses.

 

[Catastrophe]

"So the real answer is that we just don't know. There are educated guesses, but they are only guesses."

Whilst I agree with that conclusion, there are two places to find heavier elements: deep down where you can't reach them and on or near the surface, where they are accessible. The accessible variety must have arrived more recently from interstellar dust or, in more concentrated form, from a recent impact - comet dust?

Clearly the Moon had equal opportunity (allowing for size) as Earth with the advantage that any collected would "stay put".

Cat

 

[dfjchem721]

Transport can be cheap from the Moon to the surface of the Earth, but is astronomically expensive from Earth to Moon.

Helium-3 is believed to exist in large quantities on the surface of the moon by solar radiation.

It could be used for fusion reactors etc. What about mining He-3, or is that all a bunch of nonsense.

Read a little about this some time ago.

 

[Catastrophe]

Oh! Sorry. I wasn't counting He=3 (Is that ^3He?) as a heavy metal in the chemical sense, as opposed to anything higher than He in the cosmology usage. Not that it makes a lot of difference!

 

[YetAnotherBob]

Helium-3 is believed to exist in large quantities on the surface of the moon by solar radiation.

It could be used for fusion reactors etc. What about mining He-3, or is that all a bunch of nonsense.

Read a little about this some time ago.

Helium 3 on the Moon is basically solar wind trapped in the rock. It's more abundant on the Moon than it is on Earth But that's Parts per Billion, not Parts per Trillion. So it's still not really common.

But hey, it's Helium.

It's an inert gas that doesn't combine chemically with anything. It's also light so if it isn't trapped in rock crystals it just blows away.

Helium 3 is rare for us. It's a potential fusion fuel if we ever actually get fusion. So it is going to be valuable, Someday!

But it's value currently is it's scarcity.

Virtually all the Helium 3 on Earth is the product of the radioactive decay of Tritium. So here it's the product of a slow decay of a rare radioactive isotope that is itself generally the product of a radioactive decay event.

 

[dfjchem721]

Helium 3 is rare for us. It's a potential fusion fuel if we ever actually get fusion. So it is going to be valuable, Someday!

They recover tritium in reactors for thermonuclear weapons since it is a part of the fission-fusion-fission mechanism of the physics package. The fusion stage uses tritium and deuterium, if I remember this. Once ignited it creates a lot of fast neutrons that fission the U-238 tamper around the primary. Most of the power from these nukes is fission, not fusion.

If we could make tritium in significant amounts, we wouldn't need to get He-3 from the moon. The question is, can a nuclear reactor (or some other means) produce enough He-3 from tritium decay to power fusion reactors ?

Seems easier than mining it on the moon.

 

[Helio]

I vaguely recall a cool story about a metal that would vaporize lunar during daylight then become liquid at night. It was predicted and discovered to be correct, IIRC.

The vapor phase caused migration. But, with migration, concentrations occurred within craters, which block sunlight. I'm fairly sure the metal is Hg (Mercury).

Does anyone recall this story?

 

[Ken Fabian]

The accessible variety must have arrived more recently from interstellar dust or, in more concentrated form, from a recent impact - comet dust?

Not sure that would be so. Whilst heavier elements migrate corewards some still remains in the surface materials, especially if it is chemically bound as oxides, silicates or within other compounds that have lower density than the pure element. Those well mixed low concentrations are still capable of being concentrated by active geological processes - dissolved by molten rock and high temperature/high pressure water to separate and solidify in more concentrated forms, to become our higher grade ores. I don't see that it had to be added from space later for that to occur - although there will have been (still is) incoming material.

Helium-3 is believed to exist in large quantities on the surface of the moon by solar radiation.

It could be used for fusion reactors etc. What about mining He-3, or is that all a bunch of nonsense.

Read a little about this some time ago.

Until there is such a thing as a He-3 fusion reactor I think it is nonsense; we need real commercial opportunities rather than relying on thinking up non-existent carts for putting in front of non-existent horses. Isn't He-3 at 20 parts per billion on the moon? Not my idea of a viable mining prospect!

If we can produce He-3 on Earth and nuclear technological capabilities improve so much that we get He-3 fusion reactors we will probably get better at producing it on Earth.

 

[Catastrophe]

Ken:

"
At the time of the Earth's formation, and as the most noble (inert) of metals, gold sank into the core due to its tendency to form high-density metallic alloys. Consequently, it is a relatively rare metal. Some other (less) noble heavy metals—molybdenum, rhenium, the platinum group metals (ruthenium, rhodium, palladium, osmium, iridium, and platinum), germanium, and tin . . . . . . . . . otherwise occur in the crust, in small quantities, chiefly as chalcophiles (less so in their native form).

Concentrations of heavy metals below the crust are generally higher, with most being found in the largely iron-silicon-nickel core. Platinum, for example, comprises approximately 1 part per billion of the crust whereas its concentration in the core is thought to be nearly 6,000 times higher. . . . . . . . . ."
Wiki Heavy metals

c.f. alloys. My emphasis.

I think it is necessary to read the full article as there are so many differences between so-called heavy metals.