29 November 2018

ERC Consolidator Grant for Mariëtte Wolthers

Two million euros for crystal clear research into the formation of minerals

With her ERC Consolidator Grant entitled ‘CRYSTAL CLEAR’, Dr Mariëtte Wolthers plans to research how minerals are formed under natural conditions. Up until now, experiments were nearly always conducted under ideal laboratory conditions, which meant that it was not possible to make direct comparisons with natural mineral formation. The research does not only have practical applications, but it could also change our understanding of how terrestrial minerals are formed.

Crystal Clear

Minerals form from tiny positively and negatively charged building blocks – ions – that coagulate and stick to each other in three-dimensional patterns. The initial steps in this process take place in water, at a scale so small that it can only be witnessed using an electron microscope, for example. Scientists have been experimenting with creating minerals for years, working in their laboratories with the ideal ratio of positive to negative building blocks. However, natural minerals rarely develop under these ideal circumstances. The ratio of positively to negatively charged ions can sometimes differ by up to a million.

Dr Mariëtte Wolthers
Dr Mariëtte Wolthers

Charge is key

With her ERC Consolidator Grant, Dr Mariëtte Wolthers will conduct laboratory experiments forming minerals at these skewed ratios. “A surplus of positive or negative building blocks causes a charge surplus or shortage”, explains Wolthers. “That can have a huge impact on how the minerals crystallise, and how quickly. I will therefore measure the charge and determine how it influences the crystallisation process. I subsequently plan to summarise the results in a new crystallisation law, in which I will work far beyond the boundaries of the earth sciences. I like to build bridges between different disciplines; this research is grounded in earth sciences, while it hinges on theoretical physics and computational chemistry’.

Minerals outlining the history of earth

“I also want to explore whether the new crystallisation law applies in natural settings”, continues Wolthers. “Based on our current understanding, we expect minerals to form in nature, while they often form very differently, or not at all. Current understanding is still based on the laboratory experiments conducted under ideal conditions. There is a strong chance that the skewed ratios play a significant role in this respect.”

The results from CRYSTAL CLEAR will help earth scientists to determine which rocks and minerals were formed where, how quickly they were formed and under which conditions. This could potentially dramatically impact our perspective of the history of earth, as this perspective was largely shaped by studying the characteristics of minerals.

The minerals that will be investigated are -from left to right- barite (barium sulfate), calcite (calcium carbonate) and pyrite (iron disulfide)

Mineral formation in practice

A more practical application of the results of Wolthers’ research is in the use of geothermal energy, for example. In this process, warm water is pumped up from deep in the earth. When water pipes are located four kilometres underground, minimal maintenance is preferable. If we learn how to control mineral formation at such depths, we could take measures to reduce limestone formation, meaning that water pipes are less likely to become blocked.