Murmanite

murmanite

lomonosovite

lorenzenite

lamprophyllite

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Formula: Na2Ti2Na2Ti2(Si2O7)2O4(H2O)4
Sorosilicate (Si2O7 groups), murmanite group, titanium-bearing mineral
Specific gravity: 2.76 to 2.84
Hardness: 2½ to 3
Streak: Pink to red or brown
Colour: Lilac to pink, alters to silvery white-yellow, brown to black
Solubility: Decomposed by hydrochloric and sulphuric acids, leaving a silica residue
Common impurities: Zr,Fe,Ta,Mn,Mg,Ca,K,P
Environments

Plutonic igneous environments
Pegmatites

Murmanite occurs in pegmatites and associated alkalic syenites as a primary magmatic mineral or as a supergene alteration product of lomonosovite. Associated minerals include lomonosovite, aegirine, arfvedsonite, neptunite, microcline, albite, natrolite, analcime, nepheline, sodalite, eudialyte, lorenzenite, lamprophyllite, rinkite and ussingite. Alteration products include labuntsovite and belyankinite (HOM, Dana).

Localities

There are two co-type localities, the Chinglusuai River Valley and the Raslak Cirques, both in the Lovozersky District, Murmansk Oblast, Russia, in an alkaline complex (Mindat).

At the Maly Mannepakhk Mt, Khibiny Massif, Murmansk Oblast, Russia, murmanite occurs in a pegmatite in nepheline syenite associated with gutkovaite-Mn. Other minerals associated with gutkovaite-Mn here include microcline, aegirine, arfvedsonite, nepheline, eudialyte, albite, lorenzenite, loparite, aenigmatite, manganoneptunite, analcime, natrolite, stilbite, chabazite, kuzmenkoite-Mn and nontronite (Minrec 35.4.352).

At the Karnasurt Mountain, Lovozersky District, Murmansk Oblast, Russia, murmanite occurs in peralkaline pegmatites, associated with ikranite. Other minerals associated with ikranite include aegirine, microcline, lorenzenite, nepheline, lamprophyllite and arfvedsonite (Minrec 35.4.353).

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