From chemistry to crystallography: minerals and what they tell us
Did you know that minerals tell stories that go back millions of years? We met Kim Totaro, Mineralogist at the MNHNL, to learn how these natural treasures enrich our lives.
Kim Totaro, Mineralogist at Luxembourg’s Musée national d’histoire naturelle, studies minerals from both fundamental and applied angles. Her research contributes to a better understanding of the mechanisms by which mineral resources are formed. In this interview, she explains how the meticulous study of these natural materials enables us not only to reconstruct the history of the Earth, but also to enchant our daily lives with their beauty and diversity – from Luxembourg and beyond.
Can you tell us about your background, and what led you to specialize in geology and mineralogy?
My studies began in commerce. I learned accounting and economics, but that wasn't what I was passionate about. Instead, I wanted to pursue a more scientific course. My high school maths teacher encouraged me to take a different path, so I opted to study geosciences and geology, first in Montpellier and then in Liège. I then worked as a Science Communicator for the Luxembourg Science Centre, which taught me a lot about sharing knowledge with the public. One year after graduating, I finally landed my dream job at the MNHNL.
I've been interested in the Earth ever since I was a little girl, especially the story of its creation. I vividly remember my first mineralogy class: the specimens on display were so beautiful, so colourful, with perfect geometric shapes, that I could hardly believe they were real. I had to study them to understand them better.
Minerals are fascinating. Our Earth produces all this beauty naturally, and we use it to create so many different things: buildings, new technologies...
What is your role in the geology-mineralogy department at the MNHNL?
I am Prof. Simon Philippo’s curatorial assistant. We complement each other's work. Our tasks include collections management (sorting, conservation, storage) and field work (as with our recent mission to Brazil). I'm also in charge of promoting our collections through exhibitions, and popularizing science for the public. And finally, there's the whole aspect of research and scientific writing.
Currently, I'm working on minerals called phosphates, found in pegmatites (a type of rock, see Infobox). The evolution of a pegmatite can be deciphered through the study of phosphates. All this tells us something about the formation of the Earth.
In the laboratory, I carry out crystallochemical analyses (structure, atomic arrangement, chemistry). Chemistry and crystallography must be combined to define species. When it comes to analysing elements lighter than magnesium, we go to Nancy, where we have access to more advanced and precise machines.
It's a very varied job, by no means monotonous, and I really enjoy it.
Can you describe your work in the field, for example in Brazil? How are geological samples collected, identified and preserved?
In Brazil, we went to a region rich in pegmatites. These are elongated bodies of rock measuring around 100 x 30 m, containing rare minerals. They are mined locally by artisanal miners.
This is what day-to-day life is like: we identify the areas of interest on the map, then go out into the field and look for them. Sometimes they're hard to find, and we don't always have network coverage! However, pegmatites are very clear rocks, visible on aerial maps. We then head off to the mines to collect our samples. The miners are very welcoming and helpful.
We also collaborate with local researchers, including Professor Joao Adauto de Sousa Neto. Knowledge sharing is essential and benefits all parties: once the samples have been analysed, we send the results to our colleagues in Brazil, enabling them to better exploit their mines. We have built up a network of local support to help us carry out our work in the best possible conditions.
Regarding the conservation of the Museum's samples, certain parameters need to be considered to avoid deterioration: humidity, light, temperature... Our collection also includes radioactive minerals stored in a special vault.
Which Museum specimen particularly appeals to you?
Probably the entire collection! It houses so many beautiful and fascinating species. Prof. Philippo has done an extraordinary job: he has expanded the collection from 8,000 to 45,000 specimens. Some mineral species are remarkable! I'm thinking of Kunzite: it's a very large, transparent mineral, whose colour depends on the axis chosen to observe it: it can range from a pale to a very powerful pink. Apart from being beautiful, Kunzite, which belongs to the silicate family, can be mined for its lithium content.
Another fascinating piece in our collection is a transparent quartz geode containing Shattuckite inclusions: these are small, very bright blue balls of great rarity. This geode, from Congo, looks like an aquarium! A piece like this easily gives me the courage to continue my work.
We also have a collection of holotypes of great scientific value. Holotypes are the world's reference samples for any new mineral species. The MNHNL holds around fifteen of them.
Last but not least, I appreciate certain minerals that might seem less aesthetic, such as phosphates, which are often considered as waste but are rich in lithium amongst other things. It's important to showcase them and communicate about them, because if we know how to process them, they're extremely valuable.
What skills are essential in your job, apart from scientific knowledge?
This job requires patience, rigour and organization. And, of course, a lot of curiosity! Sometimes the work can be repetitive (sorting a collection, preparing samples). To study a mineral in depth, there's a whole series of analyses to be carried out; the pieces are often tiny, and concentration is essential. Analysis takes time, sometimes several months. It's a long-term job.
It's also important to have a naturalist's mind: the geological context of each sample says a lot about its genesis. An eye for detail helps us understand everything that happened in a region.
And finally, you need to be a team player; this is collaborative work. The desire to share knowledge is also essential.
Do you have any unforgettable memories or unusual anecdotes related to minerals?
In 2022, we visited a mine in Brazil that contained enormous beryls (a mineral species in the silicate group). They were over two meters long! The beryls in our collection are just a few centimetres long. The size and weight of these specimens astounded me.
When we returned from this mission, we had 60 kg of minerals in our luggage.
What upcoming projects or exhibitions are you particularly excited about ?
We'd love to launch a temporary exhibition on the rich and fascinating mineralogy of Luxembourg. There are three different metal mines in the north of the country; in one of these mines, over 50 different species of mineral were found, which is enormous! We want to highlight the little-known and impressive spectrum mineralogy in the Grand Duchy.
Eventually, I'd like to develop a project with the country's high schools, perhaps the creation of a workshop, to bring geology and mineralogy to high school students. For the moment, it's just a personal idea, but I'm very keen on it. Especially as in Luxembourg, geology isn't taught in secondary schools.
What are your hobbies outside of work?
Pottery! My husband and I both fell in love with it. Apart from the artistic considerations, I appreciate the scientific aspect of working with clay.
Pottery is a very meditative art. You must concentrate on the material, work with your hands and stay in the present moment. It's another world.
Finally, what message would you like to pass on to younger generations through your work and that of the museum?
Science is dynamic and evolving every day. It's not set in stone. MNHNL's scientific section is there to make new discoveries, and there's a place for everyone. Just be daring (especially if you're a woman!).
I hope that everyone who comes to the Museum leaves with that spark of curiosity, which enables science to evolve. That's our mission.
Interview: Diane Bertel
Editors: Monique Kirsch, Selma Weber