Special Issue Applied Mineralogist June 2022

Jolan and I wrote a short blog about our field visit to the Musha-Ntunga pegmatites and quartz veins in Eastern Rwanda (Feb 2022) with some preliminary petrographic findings on the pegmatite cores.

Read it here:

Backscatter electron image, SEM element map and Cathodoluminescence image of spodumene-quartz intergrowths on the edges of a large spodumene crystal from Musha-Ntunga drill cores.

Critical minerals in the Great Lakes region of Central Africa

April 2022

In February 2022, PhD students Jolan and Laura and I visited the tin-tantalum mines in the Musha-Ntunga area in Rwanda, licensed by Piran Resources Limited. With the help of the Piran geologists and miners, we sampled tourmaline host rocks, mineralised pegmatites and quartz veins, and looked at drill cores of fresh spodumene pegmatites to study their lithium potential. Click this link to read the news article on the website of the Africa Museum, summarizing our activities in the field.

Also in Dutch and French:

New PhD student starting

Jan 2022

I’m excited to welcome Jolan Acke as the first PhD student to join my research group. Jolan will be studying granite-hosted pegmatite systems and Nb-Ta-Sn-Li mineralisation in Rwanda. More info.

Ore Deposits Hub talk

Dec 2021

In the link below you’ll find my live streamed ODH talk and discussion on Peralkaline Magmas and Critical Metal Resources, providing an overview of recent research I have worked on within the SoSRARE and HiTechAlkCarb projects. The talk also introduces two new/upcoming papers (one on fenitisation procesess published in Geology, and one currently under revision in Economic Geology). Not my best talk ever – but hope it gives a nice overview on the peculiar world of peralkaline rocks.

Interview with KU Leuven SIM2

Sept 2021

In this interview with the KU Leuven Institute for Sustainable Metals and Minerals (SIM²) I share some thoughts on the public perception of mining and the challenges around sourcing the materials needed for the green-energy transition.

We must go ‘green’ and we must do it fast. The catch is that we cannot become carbon-neutral without mining, and we cannot become carbon-neutral if the raw materials we import were mined under unfair or unsustainable conditions. If we source our raw materials elsewhere, we – as consumers and fellow inhabitants of planet Earth – have a responsibility to make sure they were extracted to similar standards as if they were mined from our own backyards. Easy to say, not so easy to do.

Read the interview here:

“Mining of critical metals has to bring economic and social benefits to Africa”

Starting a new position!

I’m excited to announce that on April 1st 2021 I’ll be starting a new position at KU Leuven and the Royal Museum for Central Africa, where I’ll be conducting research on magmatic-hydrothermal ore deposits of Sn-W-Li-Ta-Nb-REE-P and other critical metals in Central Africa.

The past 5 years at the University of St Andrews have been wonderful, and I am grateful for the many opportunities and lovely people I met along the way!

I will miss Scotland and everyone at the School of Earth and Environmental Sciences, but am looking forward to this exciting next chapter with new areas of research and collaborations. If you are working in geological exploration in Central Africa and would like to connect/collaborate, please send me a PM.

Max Hey Medal 2021

November 2020

I am delighted and honoured to be the recipient of the 2021 Max Hey Medal by the Mineralogical Society of Great Britain and Ireland. The medal is awarded: “To recognize existing and on-going research of excellence in the fields of mineralogy, crystallography, petrology and geochemistry by an early career researcher, evidence of which is provided in the form of work published in highly-regarded, international scientific journals”.

I would like to take this opportunity to thank my nominators and supervisors (from BSc, MSc, PhD and Postdoc projects), and collaborators in the UK and abroad for their continued support and mentorship over the years.

Read more

New Paper on the Adsorption of Rare Earths in Lateritic Clay Deposits, published in Nature Communications

September 2020

Subtropical weathering profiles developed on granites in Southern China are the worlds dominant source for heavy rare earth elements (HREE); metals that are crucial in many user electronics and green technologies. In these weathering profiles, feldspars and other magmatic minerals that contain REE break down to form secondary clay minerals. In the process of soil formation, REE are released from the minerals and are generally  inferred to adsorb loosely to the surfaces of secondary minerals, dominantly clays and Fe-Mn oxides.

Although these so-called ‘ion adsorption deposits’ are typically very low grade compared to magmatic REE deposits (carbonatites/alkaline rocks), exploitation of these resources is economically viable because the REE can be extracted at low cost via surface or heap leaching. The key requirement for this to work is that the REE are indeed adsorbed to the surfaces of clay minerals, instead of being hosted in insoluble secondary or relict mineral phases.

In our new paper published in Nature Communications (Open Access: we compare the mineralogy and distribution of #REE in prospective weathering profiles from the peralkaline #Ambohimirahavavy Complex in #Madagascar to economically exploited weathering profiles from the #Zhaibei Granite in #China.

Specifically, we use X-ray Absorption Spectroscopy to find out exactly where the #REE were hiding in lateritic soil profiles from Madagascar and China.

Although primary mineralogy plays a key role in the development of easily-leachable REE deposits formed by weathering, we found that the adsorption mechanisms of REE to clay minerals, at the atomic level, are identical at both sites.

Our data demonstrates that Yttrium, as a proxy for the heavy REE, is dominantly adsorbed as 8 to 9-fold hydrated outer sphere complexes to clay minerals, dominantly kaolinite and minor halloysite. This proves the general assumption that the REE are adsorbed to clay minerals, and justifies the name ‘Ion Adsorption Clay Deposits’ for these ore types. 

Special Issue on Angola visit in the Applied Mineralogist

December 2019

I was invited to write an item for the Applied Mineralogy Group Newsletter about our recent visit to Angola. Click here to read more about the history and economy of Angola, and highlights from our fieldtrip to the Nejoio Alkaline Complex. I presented this work at the Mineral Deposit Studies Group (MDSG2020) in London this January.

Nejoio pic compilation
Figure 2A) Blue photochromic sodalite (note hexagonal inclusions in feldspar), B) Photoluminescent sodalite, C) Nejoio complex seen from the south, D) magma-mush mingling textures, E) mafic-felsic banding with strong contrast in feldspar lamination.


Article in The Conversation


Finch, Borst and Hutchison (2019) How volcanoes recycle the Earth’s crust to uncover rare metals that are vital to green technology. 

This article highlights Will’s recent 2019 paper in Nature Communications, which presented sulfur isotope data of alkaline magmas providing insights in global recycling of the Earth’s crust into the mantle via subduction, and coming back to the surface via alkaline magmatism. This article in The Conversation explains to a more general audience how volcanoes can help us understand these global element cycles related to plate tectonics, and how metal resources for the future were concentrated in this cycle.

Alkaline Igneous Rocks of Angola, workshop and fieldtrip September 2019


In September, the St Andrews team took part in a workshop and fieldcourse in Angola, hosted by the Universidade Agostinho Neto (UAN) in Luanda. The purpose of our trip was to outreach our work on alkaline igneous rocks and to learn more about similar rocks found in Angola. Our visit was funded by the SFC Global Challenges Research Fund. Read more about our visit here…

Sulfur Isotopes Paper Published in Nature Communications


Our research led by Will Hutchison on sulfur isotopes of alkaline magmas is now published Open Access in Nature Communications. The work was led by the St Andrews team in collaboration with colleagues at Tübingen and Glasgow Universities. The group at St Andrews included four of our group (Will Hutchison, Adrian Finch, Nicky Horsburgh and Anouk Borst), our colleague Eva Stüeken (who works on chalcogen isotope fractionation) and Henrik Friis who is now Associate Professor at the University of Oslo.

Will compared the mantle signatures of Gardar magmas in Greenland with a compilation of data for alkaline igneous rocks across the globe. Variations in mantle sulfur signatures matched gross trends in the isotope values of the contemporary surface, which changed dramatically over Earth History. He concluded that the sulfur in the Gardar magmas contained a component that had been recycled from the Earth’s surface.

The exciting conclusion is that the Earth’s sulfur cycle contains a significant component of surface sulfur being recycled back into the mantle. Will’s work draws attention to how useful alkaline igneous rocks are as windows on the composition of the sub-continental mantle through geological time. 

View from mile high cliffs on the Motzfeldt complex, Gardar South Greenland, one of the main sites for the study

Hutchison W, Babiel RJ, Finch AA, Marks MAW, Markl G, Boyce AJ, Stüeken EE, Friis H, Borst AM & Horsburgh NJ (2019) Sulphur isotopes of alkaline magmas unlock long-term records of crustal recycling on Earth. Nature Communications, 10, 4208.

Press Coverage

The work has received significant national press coverage including of the following:


New paper out in special Rare Earth issue of Minerals


In this study we quantify gains and losses of critical elements during late-magmatic hydrothermal alteration of eudialyte in the Ilimaussaq complex, Greenland. By microdrilling the alteration products of eudialyte – the primary host for REE, Zr and Nb – we found that certain metals (particularly those just mentioned) may be more mobile in the hydrothermal environment than we previously thought.

EudialyteAlteration-VandeVen et al 2019
Red kakortokite sample from Unit 0 showing relative proportions of fresh eudialyte (red, c. 30%), replacement products after eudialyte (brown, c. 30%) and remaining minerals (feldspar, nepheline, sodic amphibole, c. 40%)

The alteration led to significant losses in Rare Earths and other High Field Strength Elements, and small gains in Large Ion Lithophile Elements (Rb, Th, U). We suspect that the elements that were removed from eudialyte by the fluids re-precipitated elsewhere in the rock. As such we infer that the alteration did not significantly influence the overall ore grade of the deposit. However, it does influence the ease by which we can extract the metals from the rock, as the metals are now hosted in a plethora of fine-grained intergrowths of secondary minerals. This has important implications for ore potential and mineral processing schemes of eudialyte-hosted ores, if we are to exploit these as a future source for green-technology metals.

van de Ven Mathijs, Borst Anouk M, Davies Gareth R, Hunt Emma J, Finch Adrian A (2019) Hydrothermal Alteration of Eudialyte-Hosted Critical Metal Deposits: Fluid Source and Implications for Deposit Grade. Minerals 20199(7), 422;  

The paper is the result of an MSc project by Mathijs van de Ven, co-funded by the University of St Andrews, the VU University Amsterdam and SOSRARE. Mathijs graduated at the VU University Amsterdam with distinction in 2018, and now works as an exploration geologist at RSC Mining & Mineral Exploration in New Zealand.


New Ilímaussaq isotope paper in Lithos

Jan 2019

Dating agpaitic rocks: A multi-system (U/Pb, Sm/Nd, Rb/Sr and 40Ar/39Ar) isotopic study of layered nepheline syenites from the Ilímaussaq complex, Greenland, Lithos.

Happy to announce that the last paper of my PhD is now published in Lithos. In this paper we investigate how late-magmatic fluid reactions affect initial isotopic ratios of different minerals and how this affects the accuracy of isochron age dating for peralkaline rocks.

Find a link to the paper here.


EGU Geochemistry, Mineralogy, Petrology & Volcanology Blog

Below is a link to a guest blog I wrote with Dr. Will Hutchison for the EGU Geochemistry, Mineralogy, Petrology & Volcanology website.

The Fractional Crystallization Freak Zone

Will is a fellow postdoctoral researcher here at St Andrews. He studies active volcanoes and ancient magma chambers, and is currently working on the roof zones of  alkaline magmatic systems in Greenland, as part of the Horizon2020 funded HiTech AlkCarb consortium.

Click here for the HiTechAlkCarb, website and blogs


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