Gerasimovskite

minerals

ussingite

epistolite

steenstrupine-(Ce)

Images

Formula: Mn2+(Ti,Nb)5O12.9H2O (?)
Multiple oxide, manganese and niobium bearing mineral, forms a series with manganbelyankinite
Specific gravity: 2.52 to 2.58
Hardness: 2
Colour: Brown to grey or light grey
Environments

Pegmatites
Hydrothermal environments

Gerasimovskite occurs as a secondary mineral formed by the late-stage hydrothermal alteration of niobiumtitanium minerals (possibly epistolite) within ussingite-bearing pegmatites, associated with alkaline intrusions (HOM).

Localities

At the Ilímaussaq complex, Kujalleq, Greenland, gerasimovskite is associated with albite, analcime, aegirine, natrolite, chkalovite, lithian mica, epistolite, niobophyllite, monazite, rhabdophane, tugtupite, nenadkevichite and beryllite (HOM).

At the type locality, Malyi Punkaruaiv Mountain, Lovozersky District, Murmansk Oblast, Russia, gerasimovskite occurs in platy masses in ussingite-bearing pegmatites. It is believed to have formed by the hydrothermal alteration of minerals of the murmanite-lomonosovite series (AM 43.1221). Associated minerals include ussingite, epistolite, steenstrupine-(Ce) and neptunite (HOM).

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