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Author Topic: QotW - 13.08.15 - Is it possible to mine diamonds on other planets?  (Read 2263 times)

Offline evan_au

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Diamonds are made deep underground, when carbon is subjected to high pressure and heat.
Is there any way that other elements could be used to make an even harder type of diamond?
I was thinking of mining other planets where pressures may be greater due to the planet being more massive.

Is it possible to mine other planets for resources like diamond?

What do you think? Answer next week!
« Last Edit: 17/09/2013 12:34:47 by hannahcritchlow »


 

Offline evan_au

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Diamonds are found in volcanic pipes which rapidly bring carbon crystals from deep within the Earth (150 to 200km underground) to near the surface.

Some of these Kimberlite pipes have been mined down to a depth of 1km, but the ore body extends much further down. It just gets much more expensive (not to mention hot, uncomfortable and dangerous) to mine even 2.5km deep, as is done in some of the world's deepest gold mines. Even the richest of diamond ores yield a very small amount of diamond for every ton of ore crushed. Unfortunately, operating mines under these extreme conditions is only really economic if it is staffed by a near-slave labour force.

Just living on the surface of planets with higher gravity would be uncomfortable and dangerous for humans, even without the additional risks of mining. However, mining by robots may be feasible in future.

Nanodiamonds can also form in meteorite impacts on Earth and the Moon (and presumably other astronomical bodies). Astronomers even calculate that some stars which have burnt much of their hydrogen to carbon may consist primarily of diamond, however mining stellar diamonds is far beyond our current technology.

With our current technologies, interplanetary diamond mining would not be economically viable - but if one day we manage to maneuver an asteroid close to Earth, any diamonds found may attract a novelty price.

There are substances with hardness approaching diamond's "10" on Moh's Hardness Scale, including boron nitride and titanium diboride.  Another crystalline form of diamond nanorods has been made in the laboratory, and is found to be harder than the conventional "pyramid" diamond crystal structure.

Few diamonds are of "gem" quality - most are quite opaque, and are used for drill bits and cutting tools.

These days it is possible to produce diamonds in the factory for these industrial purposes. Diamond also has an interesting mix of optical, thermal and electrical properties, and thin layers of crystalline diamond can be produced by chemical vapour deposition. For future space explorers, making diamonds would probably be more practical than digging for them.
 

Offline alancalverd

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Agreed, pointless. Also remarkably difficult. Suppose you need x tons of propellant to launch 1 ton of payload from earth. Then you need 10x tons to launch 1 ton from a planet with 10 times the surface gravity. But you have to launch that ship initially from earth, so to recover 1 ton of payload you need to start with 10x^2 tons of propellant.

With x in the order of 100 using known technologies, the exercise becomes at least very expensive. But there's another side to this question:

Gem diamonds are only valuable because they are rare. The market is tightly controlled and anything that looks like a good artificial production process is subject to huge legal wrangling over patents, product labelling and market access. So any large-scale mining of gem diamonds is doomed to failure - the market price will drop in response. And there's no shortage of industrial quality material.
 

Offline CliffordK

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I was thinking of mining other planets where pressures may be greater due to the planet being more massive.

All of the planets in our solar system with a greater mass than Earth also have a much thicker atmosphere, and there is some question whether they truly have a rocky or liquid core.  Nonetheless, the temperatures at the surface of the core would be high enough that it would be difficult to work  in, and potentially not a good environment for forming diamond crystals.
 

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