Posted on 03/31/2021 7:32:11 AM PDT by Red Badger
Nature’s strongest material now has some stiff competition. For the first time, researchers have hard evidence that human-made hexagonal diamonds are stiffer than the common cubic diamonds found in nature and often used in jewelry.
Named for their six-sided crystal structure, hexagonal diamonds have been found at some meteorite impact sites, and others have been made briefly in labs, but these were either too small or had too short of an existence to be measured.
Now scientists at Washington State University’s Institute for Shock Physics created hexagonal diamonds large enough to measure their stiffness using sound waves. Their findings are detailed in a recent paper in Physical Review B.
“Diamond is a very unique material,” said Yogendra Gupta, director of the Institute for Shock Physics and corresponding author on the study. “It is not only the strongest — it has beautiful optical properties and a very high thermal conductivity. Now we have made the hexagonal form of diamond, produced under shock compression experiments, that is significantly stiffer and stronger than regular gem diamonds.”
Researchers have long wanted to create a material stronger than natural diamonds, which could have a variety of uses in industry. While many theorized that hexagonal diamonds would be stronger, the WSU study provides the first experimental evidence that they are.
Lead author Travis Volz, now a post-doctoral researcher at Lawrence Livermore National Laboratory, focused his dissertation work at WSU on the creation of hexagonal diamonds from graphite. For this study, Volz and Gupta used gunpowder and compressed gas to propel small graphite disks about the size of a dime at a speed of around 15,000 miles per hour onto a transparent material. The impact produced shockwaves in the disks that very rapidly transformed them into hexagonal diamonds.
Immediately after impact the researchers produced a small sound wave and used lasers to measure its movement through the diamond. Sound moves faster through stiffer material. Previously sound moved fastest through cubic diamond; in the lab-created hexagonal diamonds it moved faster.
Each process happened in several billionths of a second, or nanoseconds, but the researchers were able to make the stiffness measurements before the high velocity impact destroyed the diamond.
Stiffness is the ability of a material to resist deformation under a force or pressure — for instance, a rock is stiffer than rubber as rubber will bend when pressed. Hardness is the resistance to scratching or other surface deformations.
Generally stiffer materials are also harder, said Volz. While the researchers weren’t able to scratch the diamonds to test hardness directly, by measuring the diamonds’ stiffness, they can make inferences about their hardness.
If the science advances to the point where lab-made hexagonal diamonds can be created and recovered, they could have a range of uses.
“Hard materials are useful for machining capabilities,” said Volz. “Diamond has been used for a long time in drill bits, for example. Since we found that the hexagonal diamond is likely harder than the cubic diamond, it could be a superior alternative for machining, drilling or any type of application where the cubic diamond is used.”
While the industrial advantages are clear, Gupta said it is still possible hexagonal diamonds could one day be used on engagement rings. Currently lab-made cubic diamonds have less value compared to their natural peers, but hexagonal diamonds would likely be more novel.
“If someday we can produce them and polish them, I think they’d be more in-demand than cubic diamonds,” said Gupta. “If somebody said to you, ‘look, I’m going to give you the choice of two diamonds: one is lot more rare than the other one.’ Which one would you pick?”
Reference: “Elastic moduli of hexagonal diamond and cubic diamond formed under shock compression” by Travis J. Volz and Y. M. Gupta, 8 March 2021, Physical Review B. DOI: 10.1103/PhysRevB.103.L100101
We’ve been using man made diamands for decades in saw blades. That’s why it’s now economical to grind down the entire surface of a freeway.
However, they can only be made in sizes too small to be practical in jewelry, as far as I know.
This could be a big deal for jewelry, but probably only a slight improvement over existing man made diamonds for industrial use.
I’m typing this all from memory, so I could be all wet. It’s happened before - that I completely mis-remember a thing.
The diamonds in question are of a specific crystalline structure and not your normal type.............
Yes, but for industrial purposes are they really that much better?
... and while they are stiff they apparently don’t last. A perfect complement to diamonds are forever or jokes about the effects of wedding cake,
The chinese have been making a CVD synthetic diamond for some years now and have been selling it to the jewelry industry. They are being used as the small side stones and accent stones. Takes very specific machines to tell the difference. Some even have inclusions in them. We had them in our showcase. All the jewelry stores have them in the goods and they don’t know. Stinking chinese have been ripping us off in so many ways.
It’s always surprised me that the same people who pour paint on a real fur coat don’t go after people who wear diamonds, since you can’t really tell the difference between a blood diamond and a not-blood diamond.
Anything that will take down DeBeers is fine with me. Go for it. “Fake” diamonds that are indistinguishable from natural ones.... bring it on.
As for the phrase, “Blood-Diamond”, I’m guessing you mean the slave labor used to work the diamond mines.
Black slave labor at that. Oh, and the mine owners? Are usually of white European descent.
Yet, today it could be Chinese owned diamond mines, since the Chicoms are gobbling up all the resources in Africa under the auspice they are helping impoverished nations build their infrastructres.
Actually, that's not true. Man made can actually be 'perfect', whereas natural ones never are. Man made diamonds are superior in every way. I too would love to see deBeers put out of business.
They can make diamonds big enough for jewelry only federal law prevents them from being marketed as diamonds. Manufactured diamonds are virtually indistinguishable from natural, except they are perfect of nearly perfect and are relatively inexpensive to make.
The diamond jewelry industry is a joke. If not for De Beers diamond cartel artificial restricting supply with the help of law, diamonds would cost a small fraction of what they do.
I also note that they don’t go after biker gangs for wearing all that leather.
It’s much safer to throw paint on some elderly woman in a fur coat at the Met. If they go throwing paint on random women for wearing diamonds the boyfriends/husbands might knock them on their @$$es. We already know what bikers would do.
I suppose the hexagonal diamonds last longer than many marriages or engagements...
Did the researcher think of the possibilities that there could be impurities in the hex diamonds which made sound waves move faster?
I have read that wurtzite boron nitride is stronger than diamond and that hexagonal diamond was known about before this work by Gupta et al.
I’ve heard they have to dope man made rubies with a material that shows up under non-visible lighting.
Fortunately, for me, the only use I have for diamonds is industrial and my styluses for my vinyl record players.
Now that I think about it, this could be quite a bit more useful for the latter.
Pure Grown Diamonds (Gemesis Inc) announced the world’s largest lab-created diamond in April 2013, broke that record in November 2013, and then broke the record again in July 2014. The first was a 1.29 carat emerald cut, the second was a princess cut at 1.78 carat,[13] and the third was a 3 carat round brilliant white Type IIa diamond.[14]
https://en.wikipedia.org/wiki/Pure_Grown_Diamonds
So, they are a girl’s Second Best Friend?.................
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.