Images
Formula: Ce2Fe2+(CO3)(Si2O7)
Sorosilicate (Si2O7 groups), biraite group
Crystal System: Monoclinic
Specific gravity: 4.76 calculated
Hardness: 5
Streak: White
Colour: Brown
Solubility: Soluble in strong acids such as hydrochloric and nitric acids
Weakly RADIOACTIVE
Environments
Metamorphic environments
Carbonatites
Localities
At Mochalin Log, Kyshtym, Chelyabinsk Oblast, Russia, biraite-(La), together with
alexkuznetsovite-(La) and
alexkuznetsovite-(Ce), was discovered in polymineralic nodules
as brown to dark brown anhedral grains up to 0.2 × 1.2 mm2 embedded in granular aggregates consisting of
different rare earth minerals, including allanite-(Ce),
allanite-(La),
bastnäsite-(Ce),
bastnäsite-(La),
fluorbritholite-(Ce),
perbøeite-(Ce),
perbøetite-(La),
percleveite-(Ce),
percleveite-(La),
törnebohmite-(Ce) and
törnebohmite-(La)
(MM 84.4.593–607).
At the type locality, Ust'-Biraya, Biraya Fe-REE ore occurrence, Biraya and Bya Rivers confluence area, Vitim
Plateau, Irkutsk Oblast, Russia, biraite-(Ce) has been found In a vein that cuts
fenite fragments in a
carbonatite. Associated minerals include
cordylite-(Ce),
cordylite-(La), aragonite,
strontianite, strontium- and
iron- bearing dolomite,
ancylite-(Ce),
ancylite-(La),
hydroxylbastnäsite-(Ce),
daqingshanite-(Ce),
tremolite, winchite,
ferriallanite-(Ce),
törnebohmite-(Ce), cerite,
chevkinite-(Ce), belkovite,
humite, fergusonite-(Ce),
fergusonite-(Nd),
pyrochlore, baryte,
monazite-(Ce) and other unknown minerals.
Biraite-(Ce) occurs as irregular to well-shaped brown, semi-transparent, vitreous grains from 0.1 to 3 mm in
size
(EJM 17.5.715–721, HOM).
Back to Minerals