{"id":49585,"date":"2026-05-06T10:15:55","date_gmt":"2026-05-06T08:15:55","guid":{"rendered":"https:\/\/www.ssef.ch\/?p=49585"},"modified":"2026-05-06T14:54:47","modified_gmt":"2026-05-06T12:54:47","slug":"the-hidden-gem-podcast-episode-5-with-prof-dr-henry-a-hanni-on-a-life-in-gemmology-curiosity-and-the-courage-to-question","status":"publish","type":"post","link":"https:\/\/www.ssef.ch\/de\/the-hidden-gem-podcast-episode-5-with-prof-dr-henry-a-hanni-on-a-life-in-gemmology-curiosity-and-the-courage-to-question\/","title":{"rendered":"The Hidden Gem Podcast &#8211; Episode #5 with Prof. Dr. Henry A. H\u00e4nni: On a life in gemmology, curiosity, and the courage to question"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"49585\" class=\"elementor elementor-49585\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7d760c5 e-flex e-con-boxed qodef-elementor-content-no e-con e-parent\" data-id=\"7d760c5\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a7d100a elementor-widget elementor-widget-text-editor\" data-id=\"a7d100a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Recorded in the summer of 2024, this episode is a conversation with Professor Dr. Henry H\u00e4nni, who served as Director of SSEF from 1990 to 2009 and whose work helped shape modern gemmology. Henry passed away on 8 January 2025, and it is a privilege to share his voice here. Laurent Cartier \u2014 a former student of Henry&#8217;s \u2014 speaks with him about an unconventional path into science, the discoveries that pushed gemmology toward scientific rigour, the death threats and difficult truths that came with the work, and a lifelong fascination with the colour and symmetry of stones.<\/p><p>This conversation was originally recorded in Swiss German. The English version you hear is a voice-over, with Laurent Cartier reading his own words and Martin Herzog voicing Henry.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1536c68 elementor-widget elementor-widget-image\" data-id=\"1536c68\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"655\" src=\"https:\/\/www.ssef.ch\/wp-content\/uploads\/2026\/05\/podcast-Prof.Hanni_-1024x655.jpg\" class=\"attachment-large size-large wp-image-49590\" alt=\"\" srcset=\"https:\/\/www.ssef.ch\/wp-content\/uploads\/2026\/05\/podcast-Prof.Hanni_-1024x655.jpg 1024w, https:\/\/www.ssef.ch\/wp-content\/uploads\/2026\/05\/podcast-Prof.Hanni_-300x192.jpg 300w, https:\/\/www.ssef.ch\/wp-content\/uploads\/2026\/05\/podcast-Prof.Hanni_-768x491.jpg 768w, https:\/\/www.ssef.ch\/wp-content\/uploads\/2026\/05\/podcast-Prof.Hanni_.jpg 1063w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6e432be e-n-tabs-mobile elementor-widget elementor-widget-n-tabs\" data-id=\"6e432be\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;tabs_justify_horizontal&quot;:&quot;start&quot;,&quot;horizontal_scroll&quot;:&quot;disable&quot;}\" data-widget_type=\"nested-tabs.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"e-n-tabs\" data-widget-number=\"115618494\" aria-label=\"Tabs. Open items with Enter or Space, close with Escape and navigate using the Arrow keys.\">\n\t\t\t<div class=\"e-n-tabs-heading\" role=\"tablist\">\n\t\t\t\t\t<button id=\"e-n-tab-title-1156184941\" data-tab-title-id=\"e-n-tab-title-1156184941\" class=\"e-n-tab-title\" aria-selected=\"true\" data-tab-index=\"1\" role=\"tab\" tabindex=\"0\" aria-controls=\"e-n-tab-content-1156184941\" style=\"--n-tabs-title-order: 1;\">\n\t\t\t\t\t\t<span class=\"e-n-tab-title-text\">\n\t\t\t\tEnglish version\t\t\t<\/span>\n\t\t<\/button>\n\t\t\t\t<button id=\"e-n-tab-title-1156184942\" data-tab-title-id=\"e-n-tab-title-1156184942\" class=\"e-n-tab-title\" aria-selected=\"false\" data-tab-index=\"2\" role=\"tab\" tabindex=\"-1\" aria-controls=\"e-n-tab-content-1156184942\" style=\"--n-tabs-title-order: 2;\">\n\t\t\t\t\t\t<span class=\"e-n-tab-title-text\">\n\t\t\t\tGerman version\t\t\t<\/span>\n\t\t<\/button>\n\t\t\t\t\t<\/div>\n\t\t\t<div class=\"e-n-tabs-content\">\n\t\t\t\t<div id=\"e-n-tab-content-1156184941\" role=\"tabpanel\" aria-labelledby=\"e-n-tab-title-1156184941\" data-tab-index=\"1\" style=\"--n-tabs-title-order: 1;\" class=\"e-active elementor-element elementor-element-b5dd673 e-con-full e-flex qodef-elementor-content-no e-con e-child\" data-id=\"b5dd673\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b04f864 elementor-widget elementor-widget-html\" data-id=\"b04f864\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<script class=\"podigee-podcast-player\" src=\"https:\/\/player.podigee-cdn.net\/podcast-player\/javascripts\/podigee-podcast-player.js\" data-configuration=\"https:\/\/the-hidden-gem-podcast.podigee.io\/6-new-episode\/embed?context=external\"><\/script>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div id=\"e-n-tab-content-1156184942\" role=\"tabpanel\" aria-labelledby=\"e-n-tab-title-1156184942\" data-tab-index=\"2\" style=\"--n-tabs-title-order: 2;\" class=\" elementor-element elementor-element-a01294b e-con-full e-flex qodef-elementor-content-no e-con e-child\" data-id=\"a01294b\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3553757 elementor-widget elementor-widget-html\" data-id=\"3553757\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<script class=\"podigee-podcast-player\" src=\"https:\/\/player.podigee-cdn.net\/podcast-player\/javascripts\/podigee-podcast-player.js\" data-configuration=\"https:\/\/the-hidden-gem-podcast.podigee.io\/7-new-episode\/embed?context=external\"><\/script>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-911d360 elementor-widget elementor-widget-heading\" data-id=\"911d360\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Transcript<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-095b10d elementor-widget elementor-widget-text-editor\" data-id=\"095b10d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>English version only<\/strong><\/p><p>Henry H\u00e4nni: I think it&#8217;s really my fascination for gemstones themselves that led me to gemology, the beauty of colour and symmetry. It&#8217;s a bit like flowers. Gemstones are colourful. They&#8217;re symmetrical as crystals. That&#8217;s what got me hooked.<\/p><p>Show Opener: SSCF presents the Hidden Gem podcast, conversations with the world&#8217;s leading people behind the journey of gems and jewels from the source to the finished piece.<\/p><p>Laurent Cartier: Today on Hidden Gems, I&#8217;m sharing a conversation with Professor Dr. Henri H\u00e4nni, Director of SSAF from 1990 to 2009, whose work helped shape modern gemology. We recorded this interview in the summer of 2024. Henry passed away on January 8th, 2025, and it&#8217;s a true privilege to be able to share his voice, his humour, and his clarity with you now. Henri&#8217;s path into gemology was anything but conventional. From workshop assistant at a mineralogical institute to a doctorate in geology, and then to becoming director of SSEF, where he advanced gemology with scientific rigour without ever losing sight of wonder.<\/p><p>Laurent: Henry, how did you even get started with stones\u2014with gemstones? How did you get into that?<\/p><p>Henry: I\u2019ve been fascinated by the striking beauty of colour and symmetry ever since I was a little kid. That fascination led me toward plants\u2014specifically flowers\u2014and also stones. After a long journey, which included partially attending high school and a few other things, I came to a crossroads where I had to decide what I was going to do next. My father asked, \u201cSo, what do you want to do now?\u201d and I said, \u201cEither something with plants, or something with stones.\u201d<br \/>Then he took me to the botanical institute, but they said, \u201cWe only take girls.\u201d Over at the mineralogical institute, they said, \u201cYes, we could use someone in the workshop.\u201d So that\u2019s where I started, as a workshop assistant. And of course, I immediately got to know all the students there, and I really liked their lifestyle. I wanted to be one of them, so I set out to get my high school diploma\u2014took correspondence courses and evening classes. I ended up graduating high school at 24, which allowed me to start studying. It was definitely an unusual path.<\/p><p>Laurent: So you started out fueled by your passion, and later you went to university so you could put that passion into practice professionally?<\/p><p>Henry: Exactly. And I worked the whole time while I was studying, so it was like carrying a double load. But it all worked out fine.<\/p><p>Laurent: You had the drive to go into gemmology, right?<\/p><p>Henry: A strong drive, yes.<\/p><p>Laurent: Who shared that interest in stones and plants with you\u2014your father or your mother?<br \/>Henry: Neither, actually. My dad was a medical lab technician who operated on mice and rats. Not exactly the same field.<\/p><p>Laurent: But there was still some sort of scientific mindset going on\u2014an ability to observe closely, perhaps?<br \/>Henry: During those four years of high school, I had a really good biology teacher. And when you have a really good teacher, you end up thanking them for the rest of your life.<\/p><p>Laurent: Then you went on to study at the University of Basel, correct?<\/p><p>Henry: Yes, I studied in Basel, and at the same time, I kept working as a workshop assistant right up until I finished my PhD. After that, I went looking for a position that offered better pay and where my doctorate would be recognized. There was an opening at SSEF\u2014back then, it was still in Zurich\u2014and I went to introduce myself. George Bosshart said, \u201cWe could use someone like him,\u201d so he hired me.<\/p><p>Laurent: But before you actually started at SSEF, you did a lot of traveling\u2014Greenland, for example\u2014doing geological fieldwork and mapping. Were you already interested in gemstones at that time, or did that come later?<\/p><p>Henry: I quickly realized that field geology wasn\u2019t really my thing. I didn\u2019t enjoy all the heavy hiking. I was more into lab geology or mineralogy. And gemology is basically a lab-based discipline\u2014you\u2019re not trudging around outside all day.<\/p><p>Laurent: And gemmology is often seen as a \u201csoft science.\u201d I\u2019m sure you felt that attitude at the university, where some folks didn\u2019t take it too seriously. How did you handle that?<\/p><p>Henry: Back then, gemology had only a few pioneers or role models\u2014Eduard G\u00fcbelin was one of them. I watched what he was doing and noticed what else was possible, so I went ahead and did it. That mainly led me to expand instrument-based gemology\u2014using X-ray microprobe, X-ray fluorescence, FTIR, Raman, and that kind of equipment.<\/p><p>Laurent: So you basically played a big part in making gemmology a proper science\u2014really pushing it in a scientific direction. Because hardly anyone was using advanced analytical methods for gemstones back then. It was mostly microscopes and loupes\u2014even for G\u00fcbelin. That\u2019s your big contribution to gemology, isn\u2019t it?<\/p><p>Henry: I still prefer someone using a loupe over not looking at all\u2014at least they\u2019re looking. Or maybe opening one eye and closing the other with the loupe, right? (laughs) But yes, the microscope is better, and it\u2019s standard today. It\u2019s more comfortable; you can rest your arms so the image doesn\u2019t shake, which is great. It also lets you \u201cfreeze\u201d what you\u2019re seeing\u2014take slides or photos\u2014and print them. G\u00fcbelin\u2019s photo atlas, for example, is like a bible you can flip through and is a great reference for gemologists.<\/p><p>Laurent: But you weren\u2019t just in the lab all the time. You mentioned lab gemology, but you had a good friend and did a bunch of trips to gemstone-producing regions&#8230;<\/p><p>Henry: India, Pakistan\u2014very important. And Burma, too.<\/p><p>Laurent: Was there a particular trip that stands out for you?<\/p><p>Henry: Not really\u2014I just always looked forward to the next one. I really liked being in Australia, and I went to see a diamond mine in China.<\/p><p>Laurent: How was that?<\/p><p>Henry: Honestly, it was kind of monotonous. They weren\u2019t really mining anymore\u2014apparently, they\u2019d run out of diamonds. The hole was still there, and people were still poking around desperately, but there was nothing left. I also saw the Big Hole in South Africa.<\/p><p>Laurent: After all those trips and all the people you met, why do you think people search for gemstones? What\u2019s behind that fascination?<\/p><p>Henry: Personally, I was looking for gemstones to take them home with me as reliable reference samples for later scientific studies\u2014to see, for example, how much vanadium is in a Sandawana emerald, and so on. That ended up becoming a huge collection, which luckily is now at the SSEF.<\/p><p>Laurent: But you also met many people for whom it wasn\u2019t just about science, right?<\/p><p>Henry: I think it\u2019s really my fascination for gemstones themselves that led me to gemmology\u2014the beauty of colour and symmetry. It\u2019s a bit like flowers: gemstones are colourful, they\u2019re symmetrical as crystals, and later on, if they\u2019ve been tumbled, they get cut like crystals, too. I think that\u2019s something intrinsic.<\/p><p>Laurent: So part of your curiosity was just wanting to understand colour, crystallinity, how they grow, how you can tell them apart\u2026<\/p><p>Henry: To really understand it, I probably would have had to study physics\u2014like, why exactly is a sapphire blue, or why does a tourmaline turn out brown, for instance. But in practice, it\u2019s mostly about identifying what you\u2019re faced with and whether or not it\u2019s been treated. Those were the main questions. You have to stay sharp and have a good memory to understand what you see.<\/p><p>Laurent: You also brought other strengths with you when you got into this industry. You cut stones yourself, prepared them yourself\u2014so maybe you had a more hands-on approach than people who only look at the science. Did that push you to keep experimenting?<\/p><p>Henry: Yeah, it\u2019s basically a trait of mine\u2014I always feel the need to question things. If someone says something I don\u2019t think is true, I\u2019ll check it out on my own. One example is how, for years\u2014decades, really\u2014people said that a grain of sand slipping into an oyster is what forms a pearl. But I just couldn\u2019t imagine that a creature living in the sand and in the water would be bothered by a grain of sand. And how would the sand even get so deep into the flesh, where the pearl is eventually found? That kind of puzzle is what drove me forward.<\/p><p>Laurent: So, how exactly does a pearl form, then? What did you find out? Are we any smarter about it now? Do you know the answer?<\/p><p>Henry: Well, are we smarter now? I did some experiments involving injuries to the edge of the shell to see how they heal. My view is still that when the outer mantle gets injured, some of its cells get carried deeper inside, where they form kinds of cysts. The interesting part is that the edge of an oyster shell isn\u2019t always the same throughout its life\u2014when the oyster is young, the edge is in a different position than when it\u2019s older. Over time, the oyster\u2019s shell edge keeps growing outward. Early on, it produces calcite, and later aragonite, which is why most natural pearls have a brownish core at the centre and then only later develop their proper lustre around the outside. That\u2019s why you\u2019ll sometimes hear people talk about \u201cimmature pearls.\u201d If they\u2019re harvested too soon and they\u2019re still brown, nobody really wants them, so they get thrown out. Once they turn white and nacreous, then they\u2019re acceptable.<\/p><p>Laurent: You really wanted to get to the bottom of this\u2014so much so that you had the courage to cut pearls in half, even natural pearls, just to see what\u2019s inside.<\/p><p>Henry: Yes, and that had its price. It meant sacrificing a few natural pearls, but then at least we knew for sure. It was also important to publish those findings\u2014to really spread the word so other people could benefit from that knowledge.<\/p><p>Laurent: Out of all your research projects and publications, are there one or two that you\u2019re especially proud of?<\/p><p>Henry: My explanation of how cultured pearls form\u2014that was published in German, in English, and also in Chinese. I\u2019m proud of that one.<\/p><p>Laurent: There\u2019s another one I think a lot of people know about: your work on Kashmir sapphires. In 1990, you published a paper in the Journal of Gemmology\u2014it was one of the first truly scientific studies on that subject. What motivated you? Why was that topic so important?<\/p><p>Henry: Well, I noticed that some dealers were basically mislabelling stones, putting on a product label that wasn\u2019t accurate\u2014<\/p><p>Laurent: You mean, misrepresenting the origin?<\/p><p>Henry: Yeah, basically. There\u2019s a difference between Kashmir sapphire and Sri Lankan sapphire. Back then, those were two main competing origins found on the market. You can tackle the problem from different angles\u2014chemistry, spectroscopy, microscopy. Those were the tools we had at the time. We even used electron microscopy in some cases. If we were lucky enough to polish the stone down to an inclusion, we could see what it really was. Eventually, that built a database of what\u2019s probably from Kashmir and what probably isn\u2019t.<\/p><p>Laurent: And why is that label\u2014Kashmir versus Sri Lanka\u2014so important?<\/p><p>Henry: Because the price difference can be a factor of ten.<\/p><p>Laurent: And so they need gemologists to confirm that origin.<\/p><p>Henry: Yes. And that\u2019s about the time gemologists who didn\u2019t really know how to do it would just declare something to be Kashmir if they thought it might be, without actually having much evidence\u2014just going by looks. I wanted to sort of, well, cut down on that kind of approach.<\/p><p>Laurent: That probably didn\u2019t make you popular with some dealers or even some gemmologists. How did the trade react to your insistence on being so transparent and scientific?<\/p><p>Henry: My goal was to show others what to look for so they\u2019d have a chance to identify a true Kashmir sapphire. That became the publication with all those beautiful images, including rock samples from Kashmir that had sapphire crystals which we could also analyse for trace elements. It\u2019s all in the collection here\u2014Pascal Entremont, I believe, also provided us with some of these samples.<\/p><p>Laurent: But you never actually visited the Kashmir mines yourself, right? They\u2019re over 5,000 meters above sea level\u2014really tough to get to.<\/p><p>Henry: No, I never did.<\/p><p>Laurent: You also had some run-ins with Colombians over artificial resin versus oil treatments. Could you tell us a bit about that?<\/p><p>Laurent: Yes, that\u2019s when dealers started feeling overwhelmed and asked labs for help, because more and more emeralds were being treated. Before that, they didn\u2019t really mind\u2014they\u2019d just say the stones were \u201coiled.\u201d But with today\u2019s instruments, we can see exactly what kind of oil it is. I realized that in many cases, it wasn\u2019t actually oil\u2014it was some type of artificial resin. I found a way to differentiate between oil and artificial resin. You can clean the oil out, but artificial resin is much harder to remove. Once I started pointing that out, there was a big meeting in Bogot\u00e1.<\/p><p>Laurent: You couldn\u2019t go, right? I heard you even got death threats\u2014people didn\u2019t want you to show up in Bogot\u00e1 and present your findings.<\/p><p>Henry: I\u2019d better not confirm that; otherwise, they might come for me again! (laughs) Actually, a funny anecdote from Colombia: People there had such high regard for the GIA\u2014\u201cGIA, GIA, GIA,\u201d as if it was the best and only real scientific institution. At an international emerald conference, an American woman from the GIA lab was presenting, and she showed a photo of her microscopic setup with a camera on top.<br \/>Laurent: Mhm\u2026<\/p><p>Henry: She pointed at the camera and said, \u201cThis is our laser.\u201d But it wasn\u2019t a laser. There wasn\u2019t a laser to be seen anywhere! That\u2019s when it dawned on me\u2014sometimes the reputation is way bigger than what\u2019s actually going on behind the scenes. I just hope that never becomes the case for the SSEF, and so far, it seems it isn\u2019t.<\/p><p>Laurent: So did you speak up in Colombia and say, \u201cThat\u2019s not a laser\u201d?<\/p><p>Henry: No, you can\u2019t really do that\u2026<\/p><p>Laurent: You can\u2019t, yeah. Though sometimes you did speak up, right? You\u2019ve been known to voice your opinion.<\/p><p>Henry: Yeah, well, regarding those death threats in Bogot\u00e1\u2026 I remember riding in a car next to that American woman. When I got in, I let her have the window seat. She asked, \u201cDon\u2019t you want to sit here?\u201d and I said, \u201cNo, no,\u201d and once she was seated, I told her, \u201cYou know, they do a lot of shooting around here.\u201d (laughs)<\/p><p>Laurent: But she made it out just fine?<\/p><p>Henry: She made it out in one piece, yes. Just joking around.<\/p><p>Laurent: Colombia was big money, especially back then, with emeralds\u2014it was a different era, and it could\u2019ve been dangerous for you.<\/p><p>Laurent: These days, gemmology is getting more and more scientific. We have extremely advanced methods, and some people don\u2019t even bother with the microscope anymore; they don\u2019t look at inclusions themselves. What\u2019s your take on that, and what advice would you give young gemologists?<\/p><p>Henry: Well, there\u2019s a growing gap between specialists and generalists.<\/p><p>Laurent: You were a generalist?<\/p><p>Henry: I was a generalist who became a specialist, and I\u2019d suggest every specialist go back at some point and see how things look from the basic level\u2014what people are actually doing, what they\u2019re talking about. You can\u2019t really force people to do that, but it helps.<\/p><p>Laurent: So, we\u2019ve got some stones here\u2014jasper, charoite from Siberia, Russia. What are you going to do with them? Are you going to cut them?<\/p><p>Henry: I\u2019ll give them a nice shape and then polish them so they become cabochons. My hope is that gemmologists who look at them won\u2019t just test refractive indices or density, but instead say, \u201cOh, that looks like charoite, it could be charoite.\u201d Over the years, way too much time has been spent using refractometers and polariscopes to identify faceted gems. During Covid, gemmologists couldn\u2019t meet up in person, and I thought, \u201cWe can\u2019t just let a year or two go by without doing anything. Let\u2019s keep gemmology moving!\u201d So I put together a set of stones that you can tentatively identify by sight, like tiger\u2019s eye\u2014just to refresh the memory of names, or jadeite, nephrite, etc.<\/p><p>Laurent: That\u2019s really the foundation of gemmology: being able to recognize and identify. In the lab, we mostly handle rubies, sapphires, and emeralds of high-quality. But mineralogy and gemmology are actually way broader. There are hundreds of different stones you can use. You\u2019ve got a special ring you\u2019ve had for a long time with maw-sit-sit in it. Can you tell us a bit about that stone? Have you visited the mine or the village in Burma?<\/p><p>Henry: Not the exact village, but I have been to Burma a few times.<\/p><p>Laurent: What\u2019s so special about maw-sit-sit?<\/p><p>Henry: It was another instance where something didn\u2019t sound right to me, and it spurred me to investigate. At the time, Eduard G\u00fcbelin was the top gemologist in Switzerland, and he presented that material\u2014he showed it off at meetings of the SGG (Swiss Gemmological Society). Then I got hold of a sample and studied it with J\u00fcrg Meier. We found that the name he gave it\u2014\u201cchloromelanite\u201d\u2014couldn\u2019t be correct, because chloromelanite is already a term for a certain pyroxene solid solution mixed crystal. So we prepared a thin section to see what it really was. Turns out it contains jadeite, albite, kosmochlor. Maw-sit-sit is a nice gem material.<\/p><p>Laurent: That\u2019s one of the beautiful things about gemstones, right? You\u2019ve probably seen a lot of it in your 60-year career. Sometimes you get a discovery site that might only produce for a year or two, or maybe ten years or a hundred, and then it\u2019s gone.<\/p><p>Henry: Exactly\u2014it\u2019s crazy. Somebody could be eager to buy a certain stone, but suddenly it\u2019s unavailable. Nobody has it, nobody asks for it, or maybe the mine\u2019s empty.<\/p><p>Laurent: What are some examples of that? You were one of the first people to analyze Winza rubies (from Tanzania) and have a chance to study them scientifically, right?<\/p><p>Henry: Yes, that was just one of many new finds. And the main question there was origin determination\u2014how to tell them apart from rubies of other origins.<\/p><p>Laurent: I guess you\u2019ve dealt with the fact that sometimes the trade struggles to understand why origin determination can be so difficult. There can be disagreements between labs because nature is complex; there\u2019s overlap. Is that how you see it?<\/p><p>Henry: Yes, and in addition, people don\u2019t always want to accept a result that goes against their preconceived notion. They might have paid for a Burma ruby, so it must be from Burma\u2014end of story!<\/p><p>Laurent: So you had to deliver bad news sometimes?<\/p><p>Henry: I\u2019m glad I\u2019m out of some of those challenging and tense situations now. It\u2019s not fun. I even got a death threat once\u2014actually, yeah, a death threat. Right here in Basel, a woman came by and said, \u201cI\u2019m sending my husband over,\u201d and I checked his name and saw that in Belgium he\u2019d already killed someone. She wanted her ruby to be considered Burmese.<\/p><p>Laurent: And what was her ruby, actually?<\/p><p>Henry: Not Burmese. It was heated, something else.<\/p><p>Laurent: And you took that death threat seriously?<\/p><p>Henry: Of course, immediately. I went to the police, and they made a note of it.<\/p><p>Laurent: And here you still are!<\/p><p>Henry: Yes, but you do start looking over your shoulder at every street corner when something like that happens. (laughs)<\/p><p>Laurent: Let me ask: do you have a favourite gemstone? You\u2019ve seen so many\u2014hundreds of thousands of stones in your life and career. Is there one that really stands out?<\/p><p>Henry: I love garnets, because they come in various colours, they form mixed crystals, and they\u2019re easier to grasp scientifically. Take the pyralspite series, for instance\u2014you can see how the colours result from variations in chemistry. I just think garnets are amazing.<\/p><p>Laurent: Which kinds? Demantoid, tsavorite\u2014everything?<\/p><p>Henry: All of them, yeah. Demantoid, for example\u2014one day, a good friend brought me a demantoid to look at, and I realized it had been heat-treated. I\u2019d never seen a heat-treated demantoid before. Byssolite needles\u2014actually a type of hornblende containing water\u2014if you heat them enough, the water escapes and creates stress cracks. It\u2019s mind-blowing. The first time I brought that up, nobody had written about it anywhere.<\/p><p>Laurent: So you\u2019re the first one who described heat treatment of demantoid. That wasn\u2019t really known, even though they were apparently doing it in Russia. Maybe still do.<\/p><p>Henry: Yeah, and if you\u2019re just looking through a loupe in some random orientation, you might not notice those internal features or interpret them correctly.<\/p><p>Laurent: Why do they heat-treat demantoid, but not other garnets? What\u2019s the point?<\/p><p>Henry: You can tweak the ratio of Fe2+ to Fe3+, which affects the colour.<\/p><p>Laurent: So you get a better colour out of it. And you\u2019ve seen colourless garnets too, right? That\u2019s what\u2019s so fascinating about garnet\u2014it can come in every colour.<\/p><p>Henry: Colourless is just a grossular garnet with nothing in it. And that\u2019s what fascinates me\u2014it\u2019s explainable, too.<\/p><p>Laurent: It\u2019s real detective work: you see the colour, then you can dive into the science behind it.<br \/>Henry: Do you have a favourite stone?<\/p><p>Laurent: I do. I love spinel, emerald, and pearls. That\u2019s something we share\u2014I did my PhD work on pearls because you were so passionate about them and introduced me to so many contacts. I discovered a whole new world of pearls. So what is it about pearls for you? They\u2019re not geologically formed. Did it really start with that notion about a grain of sand and you just didn\u2019t believe it, so you had to dig deeper?<br \/>Henry: Yes, and also because they started showing up in the lab. In the beginning, SSEF only graded diamonds, then diamonds and coloured stones, and eventually pearls arrived.<\/p><p>Laurent: Right, SSEF was founded in 1972 as a foundation. George Bosshart was the first director, and then you became the second. How did SSEF grow so big over the past 50 years? You played a huge part in that.<br \/>Henry: I should probably explain why it didn\u2019t grow at first: there was a foundation board made up of jewelers who could directly influence the lab in Zurich. Things changed when we moved away from that environment (to Basel), and the board got a new composition, which gave us more space, physically and otherwise. Initially, they didn\u2019t want us traveling, so I paid for some trips to trade shows out of my own pocket because I felt it was necessary. Later, when I became director, SSEF covered those costs. Over time, the board\u2019s understanding grew.<\/p><p>Laurent: And you always insisted on the highest scientific standards. You never settled for the status quo\u2014you wanted more data, more knowledge, more understanding. That was a big factor, too.<\/p><p>Henry: Yeah, that kind of outlook can really give you options.<\/p><p>Henry: And you were never lazy as a scientist\u2014you, Henry H\u00e4nni, always kept pushing.<br \/>Henry: That what\u2019s fun!<\/p><p>Laurent: That\u2019s what inspires so many people who\u2019ve worked with you\u2014just staying curious. And you\u2019re still curious today about new stones, new localities. There\u2019s plenty more to discover, right? How do you see the future of gemology?<\/p><p>Henry: Hard to say. I think there\u2019ll be an even bigger gap between specialists and generalists.<br \/>Laurent: You\u2019ve met all sorts of folks\u2014collectors, buyers. Some are in it for the money, but others do it purely for the love of gems.<\/p><p>Henry: That\u2019s a mystery to me. I\u2019m not so familiar with the buyer\u2019s side because there\u2019s always the filter of the jeweler or the stone dealer in between. I really don\u2019t know the end consumers personally.<\/p><p>Laurent: Another thing: a lot of people know you as Dr. H\u00e4nni or Professor H\u00e4nni. You\u2019ve lectured all over the world, published in every gem journal.<\/p><p>Henry: I think it\u2019s great that you bring it up, but\u2026<\/p><p>Laurent: I do, because there are so many people in the trade and the gem community worldwide who know your name. I was in the US recently, and when I mentioned SSEF, several people asked me, \u201cHow\u2019s Henry H\u00e4nni doing?\u201d Your name is still widely recognized. What don\u2019t people know about you?<\/p><p>Henry: Probably that I\u2019ve been divorced twice, for instance\u2014that my work often took priority over family. And yet my daughter still loves me, which is wonderful. She\u2019s a great daughter.<\/p><p>Henry: She helps me out now that I have a harder time walking, seeing and hearing.<\/p><p>Laurent: Thinking about the next generation or the one after that, do you think there\u2019s still more to discover?<br \/>Henry: Oh yes, absolutely. But it\u2019s like adding a drop of blue ink to a whole tank of water\u2014how much does it take before you see colour appearing? Even if my two grandkids are smart and wonderful, there are still so many people out there who\u2019d rather peddle nonsense. So we need to stay curious and scientific.<br \/>Laurent: Another point: when you started out, it was a pre-digital era. Now everyone\u2019s online with smartphones\u2014even in the remotest villages in Burma, people have internet on their phones to show off stones they claim are worth a fortune. How different was it 50 years ago, with no computers or real phone lines?<\/p><p>Henry: How was it at first? Telephone\u2026<\/p><p>Laurent: Telephone, yeah\u2014or in places like Madagascar or Burma, there probably weren\u2019t phones at all. So you just had to go there yourself.<\/p><p>Henry: Yes, and I did.<\/p><p>Laurent: You\u2019ve been pretty much everywhere, right? Almost every country.<\/p><p>Henry: Not everywhere. I\u2019ve never been to West Africa, but I have been to South Africa and East Africa.<br \/>Laurent: I\u2019ve got good news for you, Henry. We\u2019ve decided to set up a new scholarship at SSEF called the \u201cHenry A. H\u00e4nni Scholarship.\u201d The requirements are that the student must come from a gemstone-producing country. We\u2019ll pay for the course, flight, and hotel.<\/p><p>Henry: No, come on!<\/p><p>Laurent: Yes, really. It\u2019s going to be called the \u201cHenry A. H\u00e4nni Scholarship.\u201d Part of the inspiration came from what we\u2019ve been discussing.<\/p><p>Henry: That\u2019s almost too great an honour.<\/p><p>Laurent: You\u2019ve shown tremendous curiosity about these countries, forged lots of wonderful contacts, and there\u2019s another topic we haven\u2019t covered as much: you\u2019ve done so much teaching, always sharing your knowledge with me, with everyone\u2014from Mogok to people all over the world.<\/p><p>Henry: I\u2019m glad we can talk about it like this, because Michael never brought that up\u2014he always had to ensure I didn\u2019t cast a shadow over him. And now, apparently, that\u2019s in the past. How do you deal with this stuff? I might not have a lot of time left, so this news makes me really happy.<\/p><p>Laurent: And why has teaching been so important to you? Some people keep their knowledge to themselves.<\/p><p>Henry: Because it bothers me when people talk nonsense. You know, \u201cwhen the shit hits the fan\u201d<\/p><p>Laurent: Then what happens?<\/p><p>Henry: Then it flies everywhere. If someone starts saying pearls form around a grain of sand, you have to clean up this nonsense one bit at a time. I wanted to prevent that. And I wanted to show that people can understand these concepts if they attend a course, see what we\u2019re talking about, refresh their high-school chemistry or physics, and pass on to their grandkids that, hey, this stuff matters.<\/p><p>Laurent: So you\u2019d say you\u2019re only a good scientist if you can explain a theory to kids?<\/p><p>Henry: I\u2019ve tried to do that.<\/p><p>Laurent: And you did it really well.<\/p><p>Laurent: So, for example, how does an emerald form? There\u2019s chromium, there\u2019s beryl\u2014how does that happen?<\/p><p>Henry: In Pakistan, I once stood on the boundary between a pegmatite and an ultrabasic rock. In a reaction zone maybe 15 to 20 centimetres wide, there are emeralds. It\u2019s incredible to see this firsthand. The ultrabasic rock released a bit of chromium, which migrated into the pegmatite, where there was already lithium and beryllium.<\/p><p>Laurent: That\u2019s what makes emeralds so rare\u2014there aren\u2019t that many places where that particular combination occurs.<\/p><p>Henry: Yes, although as the years go by, we discover more. When I started out, ruby was far rarer than it is now. I\u2019d say 30 or 40 new ruby sources have opened up since then.<\/p><p>Laurent: And these days, you\u2019re enjoying cutting cabochons, just having fun with stones?<br \/>Henry: Absolutely\u2014I love it.<\/p><p>Laurent: Do you think your unconventional path\u2014starting as a workshop assistant at the mineralogical institute, preparing samples\u2014rather than going the direct academic route, helped you keep things communicate scientific principles in simple ways for people?<\/p><p>Henry: I think it\u2019s just a knack, being able to explain things in a certain way.<\/p><p>Laurent: But have you always had that knack, or did you work at it?<\/p><p>Henry: No idea, to be honest. Were you in my lectures?<\/p><p>Laurent: Yes, I attended your lectures at the university around 2003\u20132004.<\/p><p>Henry: Were they good lectures?<\/p><p>Laurent: They sure were\u2014that\u2019s how I got interested in gemology! I was studying geology and wasn\u2019t entirely sure, then I saw your gemmology class with all your travel photos and stories. It was both scientific and very human\u2014you showed pictures of pearl farms in Tahiti, of Mogok, Colombia, Sri Lanka\u2026<\/p><p>Henry: Flash, flash, flash\u2026<\/p><p>Laurent: Yes, I realised gemology was a nice blend of science and travel and meeting people. Gems are really a microcosm of the world. Analysing diamonds\u2014or any stone\u2014can help you understand how the earth was formed, and at the same time there\u2019s so much more to it. With pearls, I was amazed at the idea of finding DNA in them, dating them, looking at corals\u2014there\u2019s always more to discover if you collaborate with specialists from other fields. And it all started when I attended your lectures. I saw it wasn\u2019t just abstract\u2014it\u2019s got its own logic, and it\u2019s exciting, colourful. So thank you for that, Henry. Thanks so much for this conversation, Henry.<\/p><p>Henry: Thank you for the interview and for the good news.<\/p><p>Laurent: Here are your stones back\u2014take them home and keep up the good cutting, Henry!<\/p><p>Laurent: Our guest was Professor Dr. Henri H\u00e4nni, a pioneering gemologist and a mentor to many in the field, myself included. That was another Hidden Gem by SSEF, the Swiss Gemological Institute. Thank you for listening.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Recorded in the summer of 2024, this episode is a conversation with Professor Dr. Henry H\u00e4nni, who served as Director of SSEF from 1990 to 2009 and whose work helped shape modern gemmology.<\/p>\n","protected":false},"author":3,"featured_media":49454,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[6],"tags":[],"library_category":[],"library_author":[],"class_list":["post-49585","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>The Hidden Gem Podcast - Episode #5 with Prof. Dr. Henry A. 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