Inside the Jewel Vault with Professor Robert Hazen

RMH: Yes, the whole assembly. Because the diamonds by themselves are beautiful. They're little gemstones. But when you put them together in this diamond anvil, so you have another world. And the thing that's so cool about diamonds is you can look through them, you can see your samples sitting there at 100,000 times atmospheric pressure as if it were sitting many miles below the surface of Earth. But you're looking into that high pressure world and studying it in ways that no one could ever do before. That was my PhD thesis, and that's what launched my scientific career for the next 20 years. I did high pressure crystallography and that's how I built a reputation that allowed me to go on and study other things.

JCC: Yeah. And I know that you've written that diamonds are scientific treasures because they preserve not only the clues about the planet's deep interior, but also its deep past. So can you explain what you mean by how diamonds can possibly give us clues about its deep past?

RMH: Oh, Jessica, this is something that I love about all minerals. And diamond is a great example - that minerals are treasure troves of information. They contain information in their elements, trace and minor elements. So diamonds, sometimes they're yellow, sometimes they're blue, sometimes they have other colours: that's often because of trace and minor elements. Diamonds contain information from isotopes because carbon can occur in a lighter form, carbon 12, or a heavier form carbon 13. And it turns out some diamonds have the carbon signature of life. That just is an astonishing thing! The carbon atoms in a diamond can have come from previous microbes that have been subducted down, brought down from the surface all the way deep into Earth's mantle. Diamonds have inclusions. They have fluid inclusions, they have solid inclusions. And those inclusions are now amongst the most treasured scientific diamonds that you can possibly find. They used to be thought of as unsightly defects in a diamond. No more! People don't think about that anymore because when they see those minerals, those are actual minerals that come from Earth's deep interior. And they reveal things about the interior that we otherwise - actual samples, in some cases from 500 miles or more deep within the planet. The fluids tell us about how carbon and metals and other elements behave deep within our planet. So diamonds have such stories to tell. They're really remarkable, in that way.

JCC: Well, that's the diamond anvil cell. Item three. Tell us why item four - this is a calcite crystal - so, tell us why that is here?

RMH: And what a shift this was. Jessica.  So I had been doing high pressure crystallography for maybe 25 years. I trained many young colleagues on how to do this. They went and set up their own laboratories. They were writing their own grants. And at a certain point, I said, wow, here I am at the Carnegie Institution for Science, where I can do anything I want to do. But I'm competing with all of my former students for the same funds, for the same kind of research projects. And I've got some ideas that I'd like to try that are completely different. And so I just made a radical shift. I said, I want to study the origin of life.

Now, that's a crazy thing for a mineralogist to say. You might say, well, origin of life, isn't that organic chemistry? That's biology. Well, yeah, but remember that the origin of life occurred on a non-living world. And what did the non-living world have? Well, it had an atmosphere, oceans, and it had rocks and minerals. And so most of us think that rocks and minerals played key roles in the origin of life. Now, I wanted to study one of the great unsolved mysteries in the origin of life, and that is, why are the molecules of life so finicky? Why are they so idiosyncratic? And one of the idiosyncrasies that's most difficult to explain is called chirality. That's handedness. If you look at your hands, you look at your left hand and your right hand, they sort of look the same, don't they? But they are mirror images of each other. And many of the molecules of life, the amino acids that build proteins, the sugars that build carbohydrates, those molecules also come in left and right-handed pairs. And what's almost impossible to understand is that life only uses left-handed amino acids. It only uses right-handed sugars. And yet, when you synthesize molecules before life, you make 50% of left and 50% of right, invariably. So how in the world did life select these molecules? And I said to myself, well, one possibility is minerals. And if you look at that big, beautiful calcite crystal.

Calcite crystal from Elmwood TN used in Origins-of-Life Research

Bob writes: (Washington DC; Age 50): In the late 1990’s I began to wonder about possible roles of minerals in the origin of life. One of the great mysteries about life is how life’s very finicky molecular building blocks were selected. For example, nature typically makes equal amounts of “left-“ and “right-handed” molecules like amino acids and sugars. But life only uses one of those—left-handed amino acids to make proteins, and right-handed sugars to make carbohydrates. I had the idea that mirror-related faces on crystals like calcite might select and concentrate molecules of opposite handedness, thus creating environments where life could get a jump-start. In 2007, we published the widely-cited results of those experiments.

JCC: Yes.

RMH:  One of the things you notice is that the adjacent crystal faces are left and right handed. They are mirror images of each other.

JCC: Yes, of course.

RMH: And the surface structures are mirror images of each other as well. So I said, Wow. What if these surfaces could select and concentrate left versus right handed molecules? And that crystal, that you see in my Jewel Vault, that crystal was used to show that left handed amino acids stick to one set of faces, and right handed amino acids stick to other faces. And it's one of my most highly cited papers. It's something that has been very influential, because while it doesn't answer the question of how did life arise, what it does do is say on early Earth and on any planet and moon that you can imagine, that there are local environments where you can select and concentrate molecules, concentrate left, concentrate right, and maybe do other interesting chemistry after that that jumpstarts life. So that's the kind of experiment that people around the world are now doing. And calcite crystals are also big and beautiful and - wow - calcite was part of the original trilobite that I found, and now we see calcite coming in again. It's just there's so many connections in one's life, and this is one that means a lot to me.

JCC: Astonishing. And thank you so much for including this. This is really a remarkable crystal. Not just any old piece of calcite, then?

RMH: Not at all. Although I think virtually any piece of calcite has the potential to do exactly this.

JCC: Yeah. Amazing.

RMH: The origin of life is a field filled with uncertainty and controversy. I like to keep a very open mind about possibilities and say that we have many, many hypotheses that can be tested and we should window them out. Other people like to fall into a favourite hypothesis and says, this is right, and everybody else is wrong… You know, science is a social endeavour. And the less we know about a subject, for sure, the more likely people are to fall into different camps and have their advocacies and so forth. But I just find it fascinating and I found that as a mineralogist, surprisingly, I can sort of stay out of much of the fray. I can advise here's how minerals could play a role to help you, here's how minerals could play a role to help this other person. And everybody seems happy with that because origin of life is hard enough. If you have more chemical opportunity introduced by the hundreds and hundreds of different kinds of minerals that are out there, well, that just gives you more chemical chances to succeed.

JCC: So this is why the calcite crystal is item four. And your ongoing work in mineral evolution, did that come about as part of this turn that your career had taken? 

RMH: In a remarkable way, Jessica, yes it did. And it's because I've been influenced all of my origin of life work by a theoretical biologist named Harold Morowitz. And Harold was a colleague at George Mason University. And I remember the day so well, December 6, 2006, when we were at a Christmas party at the house of yet another Robinson Professor Jim Trefil who has been a co-author of mine for many, many years. And Harold was sitting there with a glass of red wine and we were talking about various things and he knew that he had influenced my work and origin of life. And he sort of coaxed me into doing this. But he just, sat there, he asked a question that no one had ever asked before. It was the strangest question and it was so smart at the same time, it was a naïve question because he's a biologist, he's not a mineralogist.

And he said, well, Bob, by the way, were there, any clay minerals in the Hadean? Whoa. I said clay minerals in the Hadean? And what he was asking me, it was a very simple question. Many origin of life theories rely on clay minerals. The Hadean is the earliest period of Earth history when life was thought to originate. And so he was saying, well, if there's no clay minerals back then those theories of the origin of life that rely on clay minerals can't be correct. And I thought about it and said, well, my first response is, oh yeah, there had to be clay minerals. But more importantly said, what an amazing question! No mineralogist has ever asked a question like that because mineralogy is a field where minerals are thought of in terms of their physical and chemical properties, but not in terms of their age, or their evolution, how they've changed. And I immediately realized, oh my gosh, this is an amazing question because it implies that some minerals were present in the Hadean, but many minerals weren't. And if they weren't present in the Hadean, when did they form? How did they form? Why didn't they form in the Hadean? And why are they on Earth today?

And it was a radically new way of thinking about mineralogy that he triggered. But I guess I was just poised to be thinking this way, but I never had. And his question triggered it. For 48 hours, I didn't sleep! Jessica I sat down, I wrote notes, I wrote an outline, I started writing a paper. And that was the mineral evolution paper that would ultimately appear two years later, after many revisions. And I was scared to death that people would think this is an insane idea. Nobody should be talking this way about minerals. And yet, the more I talked with people, the more I had experts join the group, the more solid the whole thing became. And that mineral evolution paper, which appeared in 2008, has now been cited, more than 500 times, and it's been highly influential. And certainly it's set the path for my, last decade and a half.

JCC: Yeah, amazing. Pioneering. So the whole idea of deep time and the evolution of the Earth and then the evolution of complexity in minerals alongside the evolution of life, it's just a phenomenal theory for everyone to throw themselves into.

So tell us, we've gone on, a little segue from your vault. Item number five is something that comes from life. It's very much from an epoch that is giving us clues about where we might be headed with our own climate change issues. So tell us what these items are!

RMH: That's right, Jessica. Well, here again, we see the intersection of life and minerals.

JCC: Uh huh.

RMH: We all know about this, because we all have in our bodies, we have teeth, we have bones and shells of organisms also. These are all biominerals, but in this case, these are really special minerals, and what we see here are a pair of giant shark’s teeth, what are called megalodon teeth from an ancient predator from the Miocene period of Earth history, probably about 15 million,  years old. These teeth, up to about five inches long, probably came from a predator, that could have been 50ft long. One of the largest predators in the history of our planet.

JCC: Urgh horrifying!

RMH: Finding one of these teeth is an incredibly rare event. I've met a collector recently who had been looking for 25 years and only just found his very first megalodon tooth. But Margee and I, my wife and I went to the Chesapeake Bay on a particular very very cold, blustery January day. And, I went there because I knew exactly what I was going to see. It was a northwest,   wind howling. It was a new Moon. And first thing in the morning, when you have a northwest wind and a new Moon, you get very low tides. And I knew a special place where I had seen hints, I had seen broken pieces of megalodon teeth, and I said, let's go, we might just find something.

So we went there with our two little dogs. You'll see a photograph there, and that was a great day. We found four meg teeth.

But. The two big ones we found within 30 seconds of each other. We were about 100ft apart inside. She let out a scream and picked up hers. And I let out a scream and picked up mine and they clearly came from the same animal, because on the other side of those two, you see a little red band, which I've never seen in any other megalodon teeth. So clearly these two teeth were associated with each other. It's just an astonishing rare thing to find one of them. To find two in a day is just like the day you'll never forget in your life.

JCC: So that's why these megalodon if I can even say it, I'll put my teeth in and say it again. Megalodon teeth are in the vault because they're so special.

RMH: They are. This is, once again, something that has such personal connection. As well as being treasure teeth, they're very valuable. You can go buy them on eBay but they're not cheap. But we'll never sell them. I mean, it's just part of our collecting history together. It's just one of those moments you'll never forget.

JCC: Yeah. Amazing. And so thank you so much for sharing the photos of you both standing on this exceptionally, low tide with this big, expansive beach and these horrifyingly, huge looking teeth and your two tiny little dogs that would have been just a tiny morsel.

RMH: A little morsel.

JCC: Yeah. This giant 50 foot shark. Wow. So we've got five fantastic pieces now. We've got the trilobite that you collected as a child. We've got this fluorescent mineral. Is it willemite?

RMH:  Willemite, yes.

JCC: And we've got your diamond anvil cell, a very precious assemblage. We've got the one and only calcite crystal that you used in your pioneering research on chirality and homochirality. And we've got these two terrifying megalodon teeth. So what is the final item six, please?

RMH: Jessica the final item six is a real oddity. So for the last 25 years, 30 years, we've been walking the cliffs of, Calvert County, Maryland, looking at the Miocene fossils, studying them, collecting them, donating them to museums and doing research on them, which has been great. But about ten years ago, while walking along a favourite stretch of cliff, I looked down and noticed something really odd that I hadn't noticed before. And that was a black, bulbous kind of mineral on a yellow background. I said, what is that? That isn't a fossil, that's a mineral. And I'm here on Calvert Cliffs, which is supposed to be all about fossils. And since then, we have discovered the most amazing assortment of manganese oxide and hydroxide minerals that formed as the cliffs erode. And these minerals tell an incredible story. And they are almost - we haven't confirmed it yet - they're almost positively biologically deposited minerals, microbially deposited minerals.