Diamonds

[HydrogenBond]

Diamonds are a special form of matter. A diamond is essentially one 3-D molecule of carbon, where each carbon atom is colvantly bonded to four other carbon atoms in a continuous tetrahedral arrangment. Currently, science and diamond marketing tells us that diamonds took millions and millions of year to form. This time scale may need to be revived.

 

In the lab one can make diamonds in minutes or hours using anvil presses (upside down pyramids to focus lbs/ft2 into tons/in2) and high temp to form manufactured diamonds. Picture this scenario, we are near a volcano and an earthquake causes a shift in the rock creating a local anvil hotpress zone in the rock that quickly manufactures diamonds. There is plenty of experimental data to back the anvil press scenario. Diamonds are still forever, they just grew up faster.

[Eclogite]

I see no huge problem with the temperature - around 1350 C is used in commercial diamond presses, but 1.5 million psi may be rather difficult to produce and hold for several minutes.

[CraigD]

At least one commercial facility makes artificial diamonds by vacuum depositing carbon vapor (produced whipping a methane-hydrogen mixture into plasma with an ion beam), one layer of atoms at a time. (similar to techniques for building 3-d computer chips using silicon). There is practically no limit to the size that diamonds can be made using this technique. They can currently lay down about several millimeters in less than a day. See http://www.newscientist.com/article/mg18124372.700.html for a description of the process (thought not by the commercial venture I recall).

 

What I don’t understand about this process is that, after the giant carbon crystal has been deposited, it must be baked and pressed at 2000 C and pressures 50,000+ atmospheres. I would expect that, if done slowly enough, you could build diamond at 0 (vacuum) pressure. My knowledge of crystal formation is sadly lacking. :eek2:

[C1ay]

Did you happen to read this article, Very Large Diamonds Produced Very Fast?

[Dark Mind]

I already have... Twice now :eek2:. I posted a comment in response to a comment prior to mine and to bump it onto the updated topics list :).

[alxian]

wired ran an article about plasma cloud deposition last year

 

i only picked up the mag because of the nekkid chick dressed in 4000 or so diamonds and not much more... she was hot..

 

anyways, the selling point as darkmind pointed out was the diamond mobo.

 

this added to a TTFT display means that the entire computer could be made of clear materials and be orders of magnitude more complex than the glorified eniacs we are running today.

 

hologrpahic displays and persistant world computing would be some applications one could run on such systems.. only time will tell.

[HydrogenBond]

The anvil press amplifies the applied pressure. Picture an upside down pyramid. The weight on the base is amplified into the small surface area of point of the pyramid. One pound per square foot applied to the base of the upside down pyramid would become one pound square inch at the tip of the pyramid if the tip was 144th the surface area of the base; (144 lbs/ square foot at the tip).

[Dark Mind]

Haven't read the article yet, have you? :lol:

[HydrogenBond]

I am knowledgeable about synth-gems. I did R&D with rubies, sapphires and emeralds, and know a thing or two about diamonds, but plasma deposit would not happen within the crust; maybe the mantle. The point I was trying to make it that the traditional claims of natural diamond formation taking millions of years is one-sided science since other reasonable explanations are available which don't take as much time. Sometimes market hype stirs the direction of science .

[CraigD]

… but plasma deposit would not happen within the crust; maybe the mantle.

True. I don’t see how it could occur anywhere with the Earth, as the process requires a vacuum.

 

This thread’s crowd (me included) seems focused more on the engineering of artificial diamonds than the geology of natural ones.

… The point I was trying to make it that the traditional claims of natural diamond formation taking millions of years is one-sided science since other reasonable explanations are available which don't take as much time. …

This seems a reasonable claim.

 

How do you propose to prove/disprove it? Would the formation of diamonds by local anvil hotpress zones result in measurable chemical impurities distinct to the zone, or characteristic deformation of the crystalline matrix?

 

Are you proposing that all diamonds form in anvil hotpress zones, or that some form in agreement with the traditional explanation? Have you an estimate of what fraction of diamonds are formed each way?

 

PS: I’m still eager for an explanation of why plasma deposited carbon requires heat and pressure to make diamond, rather than simply forming the target crystal as each atom is deposited.

[Dark Mind]

If I'm interpreting your questions the correct way... I believe you too have failed to read this article :lol:.

 

An anvil press is no longer necessary to produce diamonds, thanks to chemicals :).

 

*Deep sigh*... chemicals... :)

[CraigD]

… I’m still eager for an explanation of why plasma deposited carbon requires heat and pressure to make diamond, rather than simply forming the target crystal as each atom is deposited.

If I'm interpreting your questions the correct way... I believe you too have failed to read this article :lol:.

 

An anvil press is no longer necessary to produce diamonds, thanks to chemicals :D.

 

*Deep sigh*... chemicals... :)

Thanks.

 

I read “Very Large Diamonds Produced Very Fast”, but was confused by its disagreement with the newscientist article “What a diamond a day makes”, which also referred to the research of Russell Hemley at Carnegie, but describes an additional step in which “Then they cut the film into gemstones and expose the rocks to temperatures of up to 2000 °C and pressures 50,000 to 70,000 times atmospheric pressure”

 

I failed to note the dates of the 2 article: 3/2004 vs. 5/2005, and the reference to a “breakthrough” in the later one. It appears that the earlier process required the second, high-temperature/high-pressure step, but the later does not.

 

My confusion is resolved. :)

 

(Sorry to have slightly threadjacked you focus of geology, HydrogenBond, but clearing up confusion like this takes temporary precedence)

[Dark Mind]

Well placed precedence, Craig. Not a problem :lol:.

[HydrogenBond]

CraigD

You are correct about the plasma deposited. That was oversight of common sense on my part. With the anvil press theory, the same local material conditons apply as geo-theory. While the pressure can be uniform 3-D and therefore indistinquishable from slow formation geo-thoery. The theory was presented to show how science can create traditions beneficial to business that are difficult to change. No amount of proof would change anything because millions of years is considered more valuable.

[UncleAl]

Diamonds are a special form of matter. A diamond is essentially one 3-D molecule of carbon

A single crystal of quartz is a big single molecule of alternating silicon and oxygen. So? Cured epoxy is also one single big molecule.

 

Currently, science and diamond marketing tells us that diamonds took millions and millions of year to form.

20 minutes from graphite to sintered industrial diamond in a commercial press. 24 hours to grow a carat single crystal from molten metal solvent. A millsecond for imploded graphite to diamond dust.

 

http://www.me.berkeley.edu/diamond/submissions/diam_intro/cphased.htm

 

causes a shift in the rock creating a local anvil hotpress zone in the rock that quickly manufactures diamonds

Can you crush a steel ball bearing between slabs of Swiss cheese? Rock does not tolerate 2.2 million psi/3200 C with nothing on the other side. The diamond formation zone is about 100 miles under your feet.

 

CVD diamond - no problem with 200 torr gas-phase deposition. Thermodynamics proposes, kinetics disposes. See Brad Pitt's PhD thesis at Stanford.

[HydrogenBond]

How about graphite anvil presses, making graphite/tiny diamond hot press composites. The next cycle the graphite/diamond composites become local anvil presses for bigger and better diamonds.

[UncleAl]

Illucid.