Belmonteite Discovered in Italy’s Ligurian Manganese Ores

A research team led by Cristian Biagioni identified a previously unknown mineral—belmonteite—in manganese‑bearing ore deposits near Savona city in eastern Liguria, Italy. Co‑investigators Jiří Sejkora and Zdeněk Dolníček helped characterize the specimen, which contains calcium, manganese, arsenic, and hydroxyl groups arranged in an unusual crystal structure.

Microscopic examination revealed that belmonteite crystallizes as small prismatic grains embedded within the host Mn ore matrix. Chemical analysis confirmed its composition of Ca₂MnAsO₆(OH), while X‑ray diffraction established a novel lattice distinct from other known arsenates. These findings confirm that the mineral is indeed a new species rather than a variant of existing compounds ¹.

The abstract states that “the genesis…is related to the circulation of As‑rich oxidizing fluids” during late‑stage ore formation, suggesting that belmonteite formed under conditions where arsenic became mobilized by fluid oxidation before precipitating into the host rock. This observation aligns with previous studies on As transport but adds a new mineralogical marker for such environments ².org].

Expert commentary indicates that identifying belmonteite could open avenues for further research into similar calcium‑manganese arsenate hydroxides and their potential applications in materials science or geology. However, practical implications will depend on additional investigations beyond the initial discovery, including stability tests and exploration of possible industrial uses.