Paper Honoured with the Howie Award by the Mineralogical Society

I am pleased to announce that the Mineralogical Society of Great Britain and Ireland have awarded the Howie Medal to one of our papers on eudialyte-hosted rare earth deposits. The award recognises the ‘best paper’ in mineralogy for the previous year and includes analysis of its “1. Novelty, 2. Inter-disciplinarity, 3. Applicability and 4. How science is advanced by the new work”.

The paper honoured was led by Anouk Borst and looked at how rare earths were hosted in eudialyte-group minerals.

The paper examined the possible sites in eudialyte into which lanthanides and Y could substitute and then used X-ray Absorption Fine Structure (XAFS) to determine where the RE actually lay. The paper showed no distinction between the siting of heavy (Y) and light (Nd) rare earths in Eudialyte.

Eudialyte is attracting global interest in the possibility that it can be used as an ore for Zr, Nb and rare earth elements. Unlike most carbonatite-based RE sources, eudialyte-hosted deposits have relatively flat RE profiles that contain a proportionately greater percentage of higher value rare earths such as Gd and Tb. Currently research is focussing on the metallurgy of eudialyte to find ways to extract these valuable critical metals.

The paper’s purpose was to work out precisely where in the structure the rare earths were hosted, since this may explain the flat rare earth profiles that make eudialyte so attractive as an ore. In addition, this study may allow us to understand more fully a) what happens during natural high temperature replacement when eudialyte breaks down to an intimate intergrowth of many minerals, and b) dissolution during metallurgy, since the local structural state of the rare earth may be preserved in any subsequent gels that are created by acidification.

Borst AM, Finch AA, Friis H, Horsburgh NJ, Gamaletsos PN, Goettlicher J, Steininger R & Geraki K (2019) Structural State of Rare Earth Elements in Eudialyte-Group Minerals. Mineralogical Magazine, 1-49. doi:10.1180/mgm.2019.50.

Anouk (lead author) on the hunt for eudialyte in the Pocos de Caldas intrusion, Brazil.