Cervandonite-Ce

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A loose crystal grouping of this rare mineral without matrix. In great condition. The Wanni glacier - Scherbadung locality, situated on the slopes of Monte Cervandone within the Binn Valley of the Goms District, Valais, Switzerland, is a specialized alpine mineral deposit. Geologically, the site is positioned within the Monte Leone nappe, a Lower Penninic structural unit consisting primarily of two-mica leucocratic orthogneisses that underwent significant metamorphism during Alpine orogenesis. Mineralization is restricted to late-stage hydrothermal fissures and quartz veins, which developed under low-temperature conditions and became heavily enriched in elements such as arsenic, titanium, iron, and rare-earth elements. The locality has never hosted commercial industrial mining or quarrying operations for metals or building stone; instead, its operational history consists entirely of seasonal field exploration and specimen mining. Systematic extraction by mineralogists and local collectors began around 1965 as glacial retreat exposed vertical cleft faces, and hand-mining of alpine-type mineral specimens has continued intermittently during the summer months into the twenty-first century. Cervandonite-Ce is a rare rare-earth arsenosilicate mineral. It occurs within alpine fissures as black, adamantine aggregates and rosette-like clusters of tabular crystals. First described from the locality in 1988, the mineral is characterized by a complex crystal structure featuring a unique statistical substitution of arsenite groups for silicate units.