New Mineral Classification, Xenolith Water Study, Fluorophlogopite Alteration

The latest issue of the European Journal of Mineralogy presents three distinct pieces of research.

First, the IMA Commission on New Minerals, Nomenclature and Classification released Newsletter 92, authored by Bosi, Hatert, Pasero and Mills. The paper outlines updated nomenclature guidelines for newly identified minerals and proposes criteria for their formal recognition in the International Mineralogical Association system ¹.

Second, Thomaidis, Ingrin, Deloule, France and Chen investigated water concentration in mantle xenoliths derived from the Allègre and Ray‑Pic volcanoes in the French Massif Central. Their work shows that hydrous-point-defect pyroxenes retain deep hydrogen signatures during emplacement and cooling, but also quantifies how much water is altered by effusive versus explosive eruption modes ¹.

Finally, Reinberg, Aspiotis, Malcherek, Peters and Mihailova studied Fe²⁺-bearing fluorophlogopite using high-temperature Raman spectroscopy. They found that at about 600 K a phonon-driven instability mobilizes interlayer K⁺ cations; above 1 100 K H⁺ delocalises and contributes to transport, while temperatures beyond 1 300 K oxidise Fe with limited dehydrogenation/dehydroxylation, leading to partial K⁺ leakage and structural decomposition ¹.