The open encyclopedia of minerals
GlossaryCite the database
Mineralogist.org
Minerals A–ZSearchCollectionsBrowse by PropertyIdentify a SpecimenCompare MineralsLocalities MapGlossaryContribute Search the Database →
Silicate

Bornemanite

Na₆(Na   )Ba₂Ti₂Nb₂(Si₂O₇)₄(PO₄)₂O₄(OH)₂F₂
Hardness3.5–4
Crystal systemMonoclinic
ClassSilicate
←PrevBorisenkoiteNextBornhardtite→
Bornemanite specimen

Whitish (somewhat platy) bornemanite with brownish (mainly beige) platy lomonosovite from the type locality for bornemanite: Yubileinaya Pegmatite, Lovozero Massif, Kola, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0

Bornemanite

Bornemanite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₆(Na   )Ba₂Ti₂Nb₂(Si₂O₇)₄(PO₄)₂O₄(OH)₂F₂.

It crystallizes in the monoclinic crystal system (space group P-1). It is a member of the Seidozerite-Lamprophyllite structural group.

Key properties: Mohs hardness 3.5–4; specific gravity 3.47–3.5; Pearly luster; optically biaxial.

IMA symbol Bma, IMA status: approved, named in 1973.

Found in the natrolite zone of alkalic pegmatites in a differentiated alkalic massif.

It is found associated with Natrolite, lomonosovite.

The mineral was named to honor Irina Dmitrievna Borneman-Starynkevich (1891–1988), Russian mineralogist specializing in Khibiny and Lovozero minerals, Institute of Geology of Ore Deposits, Petrology.

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet. Browse more B minerals or help write this entry.