Almarudite ( IMA symbol: Alr) is an extremely rare alkaline

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form m ...

silicate mineral of the cyclosilicates (ring silicates) class, with the chemical formula , from the volcanic environment of the Eifel Mountains in Germany.Mihajlović T., Lengauer C.L., Ntaflos Th., Kolitsch U. and Tillmanns E. 2004: Two new minerals, Rondorfite, Ca₈Mg[SiO₄]₄Cl₂, and Almarudite, K([],Na)₂(Mn,Fe,Mg)₂(Be,Al)₃[Si₁₂O₃₀], and a study of iron-rich Wadalite, Ca₁₂[(Al₈Si₄Fe₂)O₃₂]Cl₆, from the Bellerberg volcano, Eifel, Germany, Neues Jahrbuch für Mineralogie - Abhandlungen, 179, pp. 265-294

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References

Cyclosilicates Beryllium minerals Manganese(II) minerals Hexagonal minerals {{silicate-mineral-stub