White crystal aggregate of the rare beryllium mineral chkalovite from Yubileinaya Pegmatite, Lovozero Massif, Kola, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Chkalovite
Chkalovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₂BeSi₂O₆.
It crystallizes in the orthorhombic crystal system (space group Fddd). It is a member of the Cristobalite structural group.
Key properties: Mohs hardness 6; specific gravity 2.662; Vitreous luster; optically biaxial.
IMA symbol Ckl, grandfathered status — known before the IMA’s founding, named in 1938.
Found in veins in pegmatite in a differentiated alkalic massif (Lovozero massif, Russia); in sodalite xenoliths in an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada).
It is found associated with Manganoan pectolite, microcline, sodalite, eudialyte, neptunite, ussingite (Lovozero massif, Russia); villiaumite, ussingite, sodalite, aegirine, lovozerite.
The name refers to Valerii Pavlovich Chkalov (1904–1938), first to fly nonstop from Moscow to the USA across the North Pole.