Kayupovaite is a new mineral named in honor of Maria Mikhailovna Kayupova (1921–1980), the mineralogist who studied the Ushkatyn-III deposit (Kazakhstan), the type of locality of the described mineral. Kayupovaite is monoclinic and of space group C2/c. The mineral belongs to the group of modulated manganese phyllosilicates and is structurally related to stilpnomelane. The absence of iron in the mineral is a result of oxidative Mn–Fe fractionation during the formation of braunite-rich Mn ores.

The Ertelien and Langedalen Ni–Cu sulfide deposits are hosted in gabbronorite intrusions formed in a convergent margin. The Ertelien deposit contains contact-related sulfides, whereas the Langedalen deposit hosts massive sulfides within extensively deformed gabbronorite lenses. Both are depleted in platinum-group elements (PGEs), which could be related to a metasomatized pyroxenitic mantle source. Isotopic data support a subduction-related origin around 1550 Ma, with magmatic signatures preserved despite later alteration.

This study explains how scientists determine whether a newly found solid phase is truly a natural mineral. We refine existing guidelines by introducing updated recommendations that improve the credibility of proposals for minerals with uncertain origins. Using three examples, we show how geological and textural evidence can confirm or challenge natural authenticity. Our new checklist helps reduce misinterpretation and ensures more reliable mineral recognition.

Synthetic lepidolites and Li-muscovites have been investigated using two-dimensional cross-polarisation heteronuclear correlation magic-angle-spinning solid-state nuclear magnetic resonance spectroscopic experiments. All results show a related ordering of the tetrahedral and octahedral sheets, with more tetrahedral Al sites close to Al-rich octahedral sites preferably coordinated by OH^- anions and Si-rich tetrahedral regions close to Li-rich octahedral sites preferably coordinated by F^- anions.