Inside the Jewel Vault with Professor Robert Hazen
RMH: it's microbial poop. It comes from one place on Earth which is called Mono Lake, California, which is a really bizarre and strange place. Mono Lake is one of these isolated lakes that just gets concentrated more and more and more in salts and the element phosphorus. In fact, every living thing needs phosphorus. But in Mono Lake, the phosphorus content is ten times greater than most living things can stand,
RMH: And so the little microbes have learned how to essentially excrete that phosphate from their cells and in the process they form these just beautiful, gorgeous little colourless blade like crystals. So the crystals are beautiful, but they are in fact microbial poop. And it's also kind of sobering that not only these are these extremely rare, but every time it rains, all the hazenite crystals in the world disappear, only to be formed again. So ephemeral is - I'm humbled by having a mineral named after me. It's the only known mineral, by the way, that's only known to form through microbial action in this way it's kind of add that unique aspect, to it. Well, since I worked so much on life and minerals, it seems appropriate.
JCC: Yes, I was just about to say that's all perfect. But first of all, can we go back in time please, and start out and ask you what it was that really switched you onto this whole mineral world as a child. Tell us about your childhood, what was the influence there?
RMH: I have very supportive parents. I had very fine, science teachers when I was young. And by young I mean 2nd, 3rd, 4th, 5th grade, very formative, very influential years and I love to collect things. I would collect bottle caps, I'd collect stamps, I collect coins. And I grew up in the area of Cleveland, Ohio, where I also was very close to fossil localities. And my family would go in out on weekend. We'd look at various, outcrops and deposits and quarries, and I was able to find fossils, which was just one more way of directing my collecting instincts. But on one very, special day, when I was about ten years old, we visited a quarry near Toledo, Ohio. And there I found a real treasure. It was a complete trilobite specimen.
JCC: Oh, wow.
RMH: Now, trilobites have always been prized by collectors and scientists. To find a complete one is not something that happens every day. But for me, this little specimen, this enrolled specimen, was such a treasure. It, had a calcite shell. But then I noticed each of the little tiny eye facets of this trilobite were shiny, metallic looking, it turns out. I've now discovered those eye facets are all pyrite. And so here's this wonderful example of a fossil. And it turns out, in retrospect, it's also a wonderful example of a mineral specimen as well.
JCC: Yeah. And this is the first piece in your vault, isn't it? And you sent me a picture of it.
RMH: It is. Oh, I love that little specimen. I still have it. I treasure it. It reminds me of when I was very young, and it reminds me of how far I've come and how lucky I've been to have parents that supported me and teachers that supported me. just giving me the opportunities that are not available to all children at that point in their lives.
JCC: Well, tell me about your parents. Would you mind sharing what they did for a living?
RMH: Sure. So, my mother and father both went to the University of Illinois. They were gifted scholars. My father, as part of the ROTC contingent there. This is in, you know, what happened in 1941, World War II. So he was called away to War. They spent the war years partly,in the United States, where he trained at various camps. He was a Major in the Army at that point. And then he was part of D-Day and went to Normandy and fought in the European theatre. And that, of course, changed their lives a great deal. But he was an electrical engineer. He was part of the Signal Corps. My mom was a literary scholar and was an incredible, amongst, other things, just a mentor at home to her three children, my brother and my sister and myself. So it was a family that was very tight knit and very committed to education and bringing out the best in all three of us. I was just very lucky, as I said.
JCC: And your mother, was she a homemaker?
RMH: She was a classic homemaker, but I think at the same time, a very frustrated one. She was brilliant. She graduated at the top of her class at the University of Illinois and could have gone on. But that's when the War started. For so many people, war disrupted and changed their lives permanently. And that was her role, was to stay on the Home Front during World War II.
JCC: This curiosity, though, is something that was encouraged, and hence your very first specimen here. Is it true that you have an incredible collection of minerals of your own?
RMH: Well, it's funny. I had a big collection of minerals because, as we'll see with my second gemmy specimen, we moved to New Jersey, where there are lots of mineral localities and not so many fossil localities. But as I became a professional mineralogist, as I was associated at Harvard with one of the great mineral museums and was using their specimens and research, it always struck me as being a conflict of interest to be building my own mineral collection at the same time that I'm trying to use the mineral collections in public institutions. And so I switched back to fossil collecting because that wasn't my major field anymore. And so I began collecting with my wife. We travelled all over the world collecting trilobites,
RMH: And we had a huge collection of trilobites, 2000 or more specimens. And, a number of years ago, we began giving that collection away mostly to the Smithsonian Institution. If you go to the National Museum of Natural History, you can see, dozens of specimens that were once in our collection, because the big museums, they just don't have a budget to obtain the most amazing, the best specimens. And yet the public needs to see these things.
JCC: Yeah. Well, you've sent us this fantastic photograph of the first item in your vault, your trilobite, that you collected as a child. And it is a very detailed photo. So thank you for sharing that. And I could just about make out the eye sockets with their little glistening prisms of pyrite, which is
RMH: Yes indeed really amazing.
JCC: So, very cool. And the second piece you've just mentioned, the second piece in your vault, it's not a gem, but gemstones can exhibit this phenomenon.
RMH: Yeah. So this is a very special piece to me. The second piece. When we moved to northern New Jersey, my parents and my teachers pointed me in the direction of mineral localities in northern New Jersey. And one of the most famous, world famous localities is called Franklin, New Jersey. It's a place that was mined for lead and zinc in the 19th and 20th centuries. It has a fabulous array of rare minerals. But the most distinctive thing to me was the fact that these minerals often glow brilliantly under black light, ultraviolet light. They fluoresce bright reds and greens and blues and oranges and it's spectacular. But back in 1965, when I collected this specimen, you couldn't just go into a store and buy a portable black light that had a battery so you could go out on the dumps and collect at night. My father was an electrical engineer and so together we designed and built my own portable black light before they were generally available.
UV shortwave & longwave fluorescence in willemite rock
RMH: And so I was able to go to Franklin and collect. What's really special about this piece, though, is not only that it's a fabulous fluorescent specimen. It has some characteristics that are quite unusual. But it was collected on my third date with Margee Hindall who a couple of years later became my wife. And we've recently celebrated our 53rd wedding anniversary.
JCC: Congratulations. That's fantastic!
RMH: So, a specimen that we collected together. Boy, I'll tell you, when you’re in high school and you can find a girl who wants to come to a dump and collect minerals at night, that's a keeper. You know that we've had a great time ever since we've collected all over the world. But that one specimen is just a particularly important one in my history and brings back so many memories.
JCC: Like many fluorescent minerals, by daylight it just looks a pretty nondescript gray sort of mottled appearance. So I hope you will be able to somehow peek into the vault when the door is shut and see it fluorescing with a little UV light on. But I see, that you've also sent a picture of, portable black light box.
RMH: That's the black light we made
JCC: It looks like a satchel it’s genius!
RMH: It's like - we took aluminium sheets, we folded into a case. We found an old NiCad that's a nickel cadmium battery, which is a long life battery from the mid-twentieth century. We wrote to the Corning Glass Company and got a small piece of their ultraviolet filter glass. And we used what's called a germicidal bulb, which is a bulb that was used early on with ultraviolet radiation to kill microbes and just put it all together. Built in the little pack, it would last for three to 4 hours at night. And I remember this. Oh my gosh. I had a ‘56 Buick, the first time that we went to Franklin. And we loaded the trunk with boulders, everything up to a couple of hundred pound boulders. And we built a fluorescent rock garden, our house. But we'd load the trunk of the car with so many rocks, the headlights, the normal beams would be shining in every oncoming driver's eyes and they'd flash their lights and say, you got your bright sun. Of course we didn't. It's just that our car was the back of the car was almost scraping the ground with all the rocks that we piled into it.
JCC: You couldn’t stop yourself!
RMH: I have so many great memories, I'll tell you.
JCC: Oh, that's wonderful So where are we now? You're still at university. It was before you've gone to university. So please tell where you went for the third item in your vault.
RMH: Oh, yes, the third item. Well, this really is a gem. It's a gemstone. It's a diamond. But it's a diamond used in a very special way. I was fascinated by minerals and by crystals and by crystal structures. What happened, when I was going from MIT as a graduate student over to Harvard to get my PhD, is a colleague had invented a new device called a diamond anvil cell. And it was nothing more than two gem quality diamonds. And you know how a typical, brilliant cut diamond has a pointy end that you don't normally see?
JCC: Yeah, the culet.
RMH: Well, what this guy did was brilliant. He said, Okay, let's take that pointy end, let's polish it off so there's a little flat surface. And we'll take two diamonds like this, and we'll squeeze them together. And at those points, if you squeeze two diamonds together, you can generate incredibly high pressures. You can generate pressures 10,000, 100,000, even a million times the atmospheric pressure. And those correspond to pressures that are deep within our planet, hundreds of kilometres down in some cases. And so I used the diamond anvil cell for the very first time to squeeze crystals and see how their crystal structures changed at high pressure. so here there’re, diamonds, just like the diamonds in my wife's wedding ring. But they're used for a really brilliant, scientific opportunity to study matter at pressures way, way beyond anything that you could normally produce in a laboratory, because of diamond anvil cells.
JCC: And this is why you've got a diamond anvil cell with both the diamonds. The whole suite, the whole assemblage is sitting here in the Vault.
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.
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.
They sort of look bulbous. They're not nice crystals, they're not shiny. But these are the finest examples of these minerals in the world. And they're now specimens that we have collected and sent to virtually every major mineral museum in the world so that they are preserved, and they can be studied and examined.
These manganese minerals, burnessite and todorokite and romanechite. They're names that very few mineralogists would know. But there they are. And they form right in the cliffs, right next to where the fossils are. We found a megalodon tooth within 2ft of where these manganese minerals are forming. That's just astonishing. So there's always something new to discover. Nature is so astonishingly prolific and diverse and presents us with countless mysteries. All you have to do is look. All you have to do is go out and walk the cliffs and see what nature is showing you. And I just find that a miracle. And I feel so lucky at my, stage of career to be discovering new things, to be discovering a new mineral deposit in a place where people have walked and studied for 200 years.
RMH: Manganese minerals are very tricky. They're very difficult to study and we're making slow, progress. But that's what's fun. If you're going to answer the thing in a minute, it wouldn't be very interesting. But if it takes ten years to answer a puzzle, then you can really sink your teeth into it.
JCC: Quite right. So, talking about sinking teeth into something deep, I mentioned in your introduction, that you were the executive director of this global phenomenally exciting collaboration, the Deep Carbon Observatory. So please tell us what the highlights of this. was. It ten years that it ran?
RMH: Well, it's ten years and it keeps going on. So the Deep Carbon Observatory was just the most remarkable opportunity presented to me by the Alfred P. Sloan foundation. Now, the Sloan Foundation is an American philanthropic foundation that supports big science projects. And they were looking for something new. So I got a phone call out of the blue. Can you imagine this, Jessica? A program officer at the Sloan Foundation, said, we're thinking of starting a ten year, hundred-million-dollar project. Would you like to lead it? Now that's not your typical phone call.
And I said, what do you mean? What do you want to study? And they said, we'd like to study the deep origin of life. And I thought about it for a very, very short time. And I said, that's probably not a one hundred-million-dollar project. Because there's so much speculation. But what we really don't understand is the global carbon cycle. That is, the cycle of carbon from the crust to the core, at scales from continents, all the way down to scales of a microbe, that we have a lot of people studying the atmosphere, we have a lot of people studying the ocean, we have people studying plants and animals and soils, but we don't know how that carbon cycle of the surface connects to the deep interior. And I said, so if you want to study something really exciting and important, study the global carbon cycle, the deep carbon cycle. And so, a long story short, they funded the Deep Carbon Observatory. We had over 1200 scientists in 55 countries. We had extraordinary efforts to study carbon in various living systems, in volcanoes, in diamonds, and all sorts of environments. The first phase of that project went, on for ten years, but the second phase is still going on. And Marie Edmonds, who's a faculty, professor at Cambridge University, is now hitting that second phase. So she's a remarkable person, and she's carrying on the lead of the Deep Carbon Observatory. But what an adventure that was, and what a privilege to work with so many incredible scientists from around the world.
JCC: Wow. So we've come to the end of your vault. We've got these six incredible pieces that are well, they're not jewels, but they are jewels, of the mineral world and of your career. So we've got your trilobite, the first specimen that you collected as a little nipper. We've got item two, the fluorescent mineral, willemite. We've got item three, which is the assemblage the whole diamond anvil cell that was so central to your work for so long. We've got item four, which is this wonderful calcite crystal that you actually performed experiments on that you based your important research paper upon. These two astonishingly fiercesome megalodon teeth that were a once in a lifetime find, truly. And this extraordinarily new form of biomineralized manganese, this bizarre merging of fossil, mineral and chemical that you found and I know you're going to want to keep them all, but just if you could only keep one, what would it be?
RMH: It's so unfair. I look at them and I think with such, incredible memories the trilobite, the fluorescent mineral, the fossil sharks teeth which were collected in such memorable and special ways, inform my life. The research specimen, the diamond anvil cell and the calcium crystal that played a research role.
But if I had to choose, I always look forward. And I still don't understand those manganese mineral specimens. And I would want to spend my time with one specimen on the thing that I have yet to understand, that I want to study, that I want to document and share with other people, to learn the story of those rocks. Because every rock is a time capsule and these strange manganese minerals are time capsules that no one has opened yet. So what is exciting - the Jewel Vault. Well, within the Vault, there is a time capsule, and that's what I'd spend my time with.
JCC: Okay, well, that's just the best choice, and I love the reason for it. So many thanks indeed, Bob, for coming on to the podcast and sharing your life and your career through these six amazing objects.
RMH: What a pleasure, Jessica. Thank you so much. Best to you and your audience.