Meet Simon Philippo: Geologist and Mineralogist at MNHNL

Simon Philippo, geologist and mineralogist at MNHNL, inspires us with his highly prolific work. Discover his journey in our new interview.

We have the pleasure of introducing Simon Philippo, a passionate mineralogist and expert at Luxembourg's Musée national d'histoire naturelle.

For three decades, Simon has meticulously studied the mineral riches of Luxembourg and beyond.

His work enhances our understanding of the composition and history of the Earth. In this interview, he shares insights into his career, his current work, and his views on future developments in mineralogy.

Mr. Philippo, what does a mineralogist do?

Mineralogy is a branch of geology. More precisely, it is the study of everything that revolves around the Earth and the Earth's structure.

Minerals are natural objects with unique chemical compositions and atomic arrangements: this is the definition of a crystal.

Mineralogists study their arrangement and grouping, known as paragenesis. This provides information about the Earth’s history and possible applications in everyday life.

What are the practical applications of mineralogy?

Minerals or their derivatives are ubiquitous: objects made of metal, for example, are transformed minerals; cooking salt; ceramics; telephones with mineral-derived components; lithium batteries... Minerals are finding more and more applications, particularly in the field of energy transition. We need additional chemical elements, and to find them, we need to study the minerals that contain them.

A year ago, an ambitious European programme, the Critical Raw Materials Act (see Infobox), was launched. It is the logical continuation of the energy transition and should enable us to find our own resources in Europe. This is a great opportunity for mineralogy. A project like this will make it easier to study our subsoil, thanks to the drilling points enabling in-depth analysis. Subsoils below 100 to 200 meters are relatively poorly understood.

This project will also strengthen our collaboration with international research teams in Europe and improve the application of environmental regulations in relation to deposits exploited in certain countries.

As a geologist, what is special about Luxembourg?

The diversity of terrain and soils in the Grand Duchy is a little like its cultural diversity. It's a true crossroads of languages, knowledge, lifestyles, and geology! The northern part (Éislek), a continuation of the Ardennes and the Rhineland-Palatinate,  an enormous schist massif. Gutland, with the Minette, is essentially a series of formations linked to the Paris Basin. Everything is interconnected. Geology knows no boundaries.

How did you become curator at MNHNL? What was your career path?

I attended a Catholic secondary school before studying geology at the universities of Namur and Louvain-la-Neuve. On the practical side, I was lucky enough to meet several mineral collectors with whom I spent a lot of time. I then worked as a farm labourer.

Some collector friends then asked me to be the scientific supervisor for a large mineral exhibition near Namur. The former MNHNL director visited; he was finishing the Museums’ renovation and searching for its first temporary exhibition. That became my first job at the MNHNL.

What inspired you to become a geologist?

It's been a passion of mine for a very long time. I've always loved observing nature. The first thing that inspired me was collecting small rocks when I was a child: I'd go to the quarries or mountains to collect samples. I was also lucky enough to have a teacher at secondary school who gave fascinating geology lessons. 

What's daily life like in the field?

It's a bit like detective work. You must ask relevant questions, then look for answers, and combine them to come up with an interesting solution.

Analysing field-collected samples, writing reports or publications takes several months. The work is divided between the very pleasant fieldwork and the research and writing aspect. There's also administrative work, of course: managing staff, budgets, collections, etc.

Thanks to some very substantial donations, we currently have 45,000 mineral samples in the museum! All these samples must be stored, labelled, encoded, preserved, and analysed. This is what I call home-mining: the study of minerals that have already been catalogued. Museums play an important protective role. Samples must be preserved to prevent deterioration, as some are no longer found in their natural environments. But each sample can be used for future analyses. Ultimately, it's a huge library just waiting to be studied.

And finally, we have several international projects in Brazil, Mozambique, the Congo, and elsewhere.

You've just returned from Brazil: can you tell us about this project?

Our mission, with my colleague Kim Totaro, took place in the north-east of Brazil, 300km off the coast, in an area known to be very rich in pegmatite. Pegmatite is a granite-like rock containing large minerals, some of which are very rare.

There were three reasons for this project: first, it is a collaboration with Professor João Adauto de Sousa Neto from the University of Recife. Together, we study these pegmatite deposits as part of a Brazilian FNR project.

The second reason is my colleague Kim Totaro’s research project. Her work focuses on a group of minerals called magmatic rock phosphates. These minerals, which are difficult to study, reveal the entire history of the rock's genesis. Kim uses samples from our collection in Brazil, which contains around 15,000 specimens, to which she adds on-site collected samples.

And finally, I went to Brazil to pursue my own research projects. I work on rare minerals that are found only sporadically in certain pegmatites. These minerals offer a whole range of information about the genesis of the rock.

The MNHNL has already discovered two new holotypes in Brazil (see Infobox).

If you had unlimited research funds, how would you use them?

I would organise a call for research candidates to conduct home-mining, the study of our collections. When a mine closes, we lose access to the samples, except through these collections. Three new species have been discovered in our collections in recent years. At MNHNL, there is work for whole generations of researchers!

In the future, the analytical resources at our disposal will continue to evolve. Some samples cannot yet be studied in detail because their structure is too small or complex. Soon, this will no longer be an issue.

Which discovery fascinated you the most?

Luxembourgite. This is the first new species found in Luxembourg. Luxembourgite is a mineral with a rather exotic chemical composition: it contains silver, lead, copper, bismuth, and selenium, but no sulphur. This makes it very special.

Luxembourgite was found near the former Stolzembourg copper mine, close to Vianden. It is made up of microfibers around 150 microns long and only a few dozen microns thick, assembled in geodes. This particular aspect made studying it long and complex, requiring international collaboration with the help of cutting-edge machinery.

Discovered in 2015, Luxembourgite was finally validated by the IMA in 2018. It has since been found elsewhere in the world, including in the Vosges mountains, Bolivia, and Germany.

(Editor's note: Luxembourgite is a rare mineral. More precisely, it is a complex sulphosalt. A sulphosalt is a type of mineral composed of sulphur, metal, and semi-metallic elements such as antimony, arsenic, and bismuth. Luxembourgite is characterised by its metallic grey colour and its crystallisation into fine fibrous needles).

What advice would you give to future young scientists?

Follow your passion, even if some will try to discourage you. If you believe in it deep down, then you must persevere.

Do you have any final thoughts you’d like to leave us with? 

The MNHNL is an emerging museum for Earth sciences. We are regularly invited to the biggest exhibitions in Europe to display our samples. The work of our scientists is paying off and we are gaining increasing international exposure.

Interview : Diane Bertel

Editors : Monique Kirsch, Selma Weber