Images
Formula: Ta(BO4)
Monoborate of tantalum
Crystal system: Tetragonal
Specific gravity: 7.86 measured, 7.91 calculated
Hardness: 7 to 7½
Streak: White
Colour: Greyish pink, pale lilac, colourless to white
Solubility: Insoluble in hot or cold acids
Environments
Béhierite is a very rare mineral, occurring in granite
pegmatites
(HOM).
Localities
At the type locality, Manjaka, Sahatany Valley, Ibity, Antsirabe II District, Vakinankaratra, Madagascar, four
greyish-pink pseudo-octahedral crystals of béhierite, 0.5 to 7.0 mm in size, were found in a complex
lithium - cesium -
tantalum granite
pegmatite hosted in
marble. Associated minerals include
albite, manganese-bearing
fluorapatite, pollucite,
polylithionite-trilithionite
series minerals, quartz and
tourmaline
(Mindat).
Béhierite from Manjaka - Image
At the Antsongombato gem mine, Antsentsindrano, Anosiarivo Manapa, Betafo District, Vakinankaratra, Madagascar,
béhierite is associated with schiavinatoite,
rhodizite,
elbaite–liddicoatite,
quartz and feldspar
(HOM)
Béhierite from the Antsongombato Gem Mine -
Image
At the Animikie Red Ace pegmatite, Pine River pegmatites, Fern, Florence County, Wisconsin, USA, small, transparent,
colourless to white crystal grains of béhierite up to 400 microns in size have been discovered in the wall
zone of the pegmatite, associated with abundant pink to red
elbaite, albite,
tantalite-(Mn), quartz
and blue manganapatite.
The presence of béhierite in the wall zone of the
pegmatite testifies to the very high
boron activity that was present at the time of crystallisation and that is
essential for the formation of this exotic mineral
(R&M 77.170).
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