New Minerals Discovered: Exsolution Textures, Belmonteite, Fengruiite

The latest issue of the European Journal of Mineralogy includes a paper on how microscopic exsolution textures in Fe–Ti oxide minerals affect crushing strategies and the pre‑concentration of vanadium and titanium. Thomas Daniel van Gerve, Philippe Muchez, Ted Nuorivaara, and Olivier Namur describe that certain textures tightly intergrow minerals and hinder separation, while others form coarser structures that improve processing by magnetic and flotation methods. Identifying these textures is essential for optimizing ore processing and resource use.¹

A second article introduces Belmonteite, CaMn₂(AsO₄)₂(H₂O)₅·2H₂O, an arsenate mineral found in the Mn ore deposits of Graveglia Valley, eastern Liguria, Italy. Cristian Biagioni, Jiří Sejkora, and Zdeněk Dolníček detail its crystal structure, which shows {010} layers of six‑fold coordinated Mn atoms decorated on both sides by (AsO₄) groups and Ca atoms connected through hydrogen bonds. The genesis of this mineral relates to circulation of As‑rich oxidizing fluids within the deposits, and it was named after Donato Belmonte for his contributions to Ligurian mineralogy.¹

The third study reports Fengruiite,, a new Ag–Sb–Te sulfosalt discovered at the Haopinggou Ag–Pb–Zn–Au deposit in eastern Qinling, China. Yongfei Tian, Guowu Li, Ningyue Sun, Min Liu, Jingwen Mao, Yunpeng Dong, Peng Liu, Wei Jian, Wei Yao, Xiuquan Wang, and Huishou Ye describe that tellurium-rich structures help trap and concentrate silver in hot mineral‑forming fluids, offering clues about how silver‑rich deposits form.¹