Figure 8. Chkalovite crystals (1): (a) in manaksite (2), from the “Palitra” pegmatite, Mt Kedykvyrpakhk, Lovozero; (b) in villiaumite (3), from a sodalite-microcline-aegirine vein in urtite, Mt Koashva, Khibiny. — Photo: Lyalina, L.M.; Selivanova, E.A.; Zozulya, D.R.; Ivanyuk · CC BY 4.0
Manaksite
Manaksite is an IMA-recognized mineral species in the silicate class, with the chemical formula KNaMn²⁺Si₄O₁₀.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Litidionite structural group.
Key properties: Mohs hardness 5; specific gravity 2.73; White streak; Vitreous luster; optically biaxial.
IMA symbol Mnk, IMA status: approved, named in 1990.
Found in ultra-agpaitic pegmatites in a differentiated alkalic massif.
It is found associated with Nepheline, sodalite, analcime, potassic feldspar, albite, cancrisilite, arfvedsonite, aegirine, ussingite, makatite, grumantite, lomonosovite, villiaumite.
The name refers to MAnganese; sodium, NAtrium; potassium, Kalium; and SIlicon in its composition.