Biraite-(Ce)
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Biraite-(Ce)
Formula:
Ce2Fe2+(Si2O7)(CO3)
Colour:
Brown
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
4.76 (Calculated)
Crystal System:
Monoclinic
Member of:
Name:
After the type locality in the Biraya Fe-REE ore occurrence, Vitim Plateau, Buriatia (Buryatia) Republic, Transbaikalia (Zabaykalye), Eastern-Siberian Region, Russia. The suffix denotes the dominant rare-earth element, following the IMA Levinson rule.
Unique Identifiers
Mindat ID:
27384
Long-form identifier:
mindat:1:1:27384:2
Similar Names
| Baierite | A synonym of 'Columbite' | |
| Baryte | A valid IMA mineral species - grandfathered | BaSO4 |
| Berryite | A valid IMA mineral species | Cu3Ag2Pb3Bi7S16 |
| Biraite | A synonym | |
| Biraite-(La) | A valid IMA mineral species | La2Fe2+(CO3)(Si2O7) |
| Birmite | A synonym of 'Burmite' | |
| Burroite | A valid IMA mineral species | Ca2(NH4)2(V10O28) · 15H2O |
| Liraite | A valid IMA mineral species | NaCa2Mn22+[Fe3+Fe2+]Mn22+(PO4)6(H2O)2 |
IMA Classification of Biraite-(Ce)
Classification of Biraite-(Ce)
9.BE.90
9 : SILICATES (Germanates)
B : Sorosilicates
E : Si2O7 groups, with additional anions; cations in octahedral [6] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
E : Si2O7 groups, with additional anions; cations in octahedral [6] and greater coordination
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Bia-Ce | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Biraite-(Ce)
Vitreous
Transparency:
Translucent
Colour:
Brown
Streak:
White
Hardness:
5 on Mohs scale
Tenacity:
Brittle
Density:
4.76 g/cm3 (Calculated)
Optical Data of Biraite-(Ce)
Type:
Biaxial (-)
RI values:
nα = 1.785 nβ = 1.81 nγ = 1.82
2V:
Measured: 66° , Calculated: 64°
Max. Birefringence:
δ = 0.035
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate
Dispersion:
r < v, weak
Pleochroism:
Non-pleochroic
Chemistry of Biraite-(Ce)
Mindat Formula:
Ce2Fe2+(Si2O7)(CO3)
Element Weights:
Crystallography of Biraite-(Ce)
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 6.512 Å, b = 6.744 Å, c = 18.94 Å
β = 111.9°
β = 111.9°
Ratio:
a:b:c = 0.966 : 1 : 2.808
Unit Cell V:
771.1 ų
Z:
4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.41 Å | (40) |
| 3.61 Å | (40) |
| 3.30 Å | (50) |
| 3.14 Å | (40) |
| 2.92 Å | (100) |
| 2.65 Å | (50) |
| 2.23 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 36 : Carbonatites, kimberlites, and related igneous rocks |
Type Occurrence of Biraite-(Ce)
General Appearance of Type Material:
Irregular to well-shaped grains from 0.1 to 3 mm in length.
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia, #91375.
Geological Setting of Type Material:
Carbonatite dyke.
Associated Minerals at Type Locality:
Synonyms of Biraite-(Ce)
Biraite (in part)
Other Language Names for Biraite-(Ce)
Dutch:Biraiet-(Ce)
German:Birait-(Ce)
Norwegian:Biraitt-(Ce)
Russian:Бираит-(Се)
Simplified Chinese:碳硅铁铈石
Traditional Chinese:碳矽鐵鈰石
Relationship of Biraite-(Ce) to other Species
Member of:
Other Members of Biraite Group:
| Alexkuznetsovite-(Ce) | Ce2Mn(CO3)(Si2O7) | Mon. 2/m : P21/b |
| Alexkuznetsovite-(La) | La2Mn(CO3)(Si2O7) | Mon. 2/m : P21/b |
| Biraite-(La) | La2Fe2+(CO3)(Si2O7) | Mon. 2/m : P21/b |
Common Associates
Associations Based on Photo Data:
| 6 photos of Biraite-(Ce) associated with Ferriallanite-(Ce) | (CaCe)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 4 photos of Biraite-(Ce) associated with Cordylite-(Ce) | NaBaCe2(CO3)4F |
| 4 photos of Biraite-(Ce) associated with Ferriperbøeite-(Ce) | CaCe3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 4 photos of Biraite-(Ce) associated with Törnebohmite-(Ce) | Ce2Al(SiO4)2(OH) |
| 4 photos of Biraite-(Ce) associated with Strontianite | SrCO3 |
| 4 photos of Biraite-(Ce) associated with 'Strontium-rich Calcite' | (Ca,Sr)CO3 |
| 2 photos of Biraite-(Ce) associated with Hydroxylbastnäsite-(Ce) | Ce(CO3)(OH) |
Related Minerals - Strunz-mindat Grouping
| 9.BE. | Zinkgruvanite | Ba4Mn2+4Fe3+2(Si2O7)2(SO4)2O2(OH)2 |
| 9.BE. | Calciomurmanite | (Na,◻)2Ca(Ti,Mg,Nb)4[Si2O7]2O2(OH,O)2(H2O)4 |
| 9.BE. | Cámaraite | Ba3Na(Fe2+,Mn)8Ti4(Si2O7)4O4(OH,F)7 |
| 9.BE. | Alfredcasparite | Sr2TiO(Si2O7) |
| 9.BE. | Batievaite-(Y) | Y2Ca2Ti(Si2O7)2(OH)2(H2O)4 |
| 9.BE. | Nacareniobsite-(Y) | Na3Ca3YNb(Si2O7)2OF3 |
| 9.BE. | Alexkuznetsovite-(Ce) | Ce2Mn(CO3)(Si2O7) |
| 9.BE. | Bobshannonite | Na2KBa(Mn,Na)8(Nb,Ti)4(Si2O7)4O4(OH)4(O,F)2 |
| 9.BE. | Paralomonosovite | Na6◻4Ti4(Si2O7)2[PO3OH][PO2(OH)2]O2(OF) |
| 9.BE. | Madeiraite | Na2Ca2Fe2Zr2(Si2O7)2O2F2 |
| 9.BE. | Bortolanite | Ca2(Ca1.5Zr0.5)Na(NaCa)Ti(Si2O7)2(OF)F2 |
| 9.BE. | Longshoushanite-(Ce) | Ce4MgAl2Ti2(Si2O7)2O8 |
| 9.BE. | Moxuanxueite | NaCa6Zr(Si2O7)2OF3 |
| 9.BE. | Delhuyarite-(Ce) | Ce4Mg(Fe3+,W)3◻(Si2O7)2O6(OH)2 |
| 9.BE. | Christofschäferite-(Ce) | Ce3CaMnTiFe3+Ti2(Si2O7)2O8 |
| 9.BE.X | Asimowite | Fe2+4O(Si2O7) |
| 9.BE. | Biraite-(La) | La2Fe2+(CO3)(Si2O7) |
| 9.BE. | Pilanesbergite | Na2Ca2Fe2Ti2(Si2O7)2O2F2 |
| 9.BE.02 | Wadsleyite | Mg4O(Si2O7) |
| 9.BE.02 | Ohtaniite | Mg3(Si0.5◻0.5)Si2O8 |
| 9.BE.05 | Lawsonite | CaAl2(Si2O7)(OH)2 · H2O |
| 9.BE.05 | Hennomartinite | SrMn3+2(Si2O7)(OH)2 · H2O |
| 9.BE.05 | Cortesognoite | CaV2(Si2O7)(OH)2 · H2O |
| 9.BE.05 | Noelbensonite | BaMn3+2(Si2O7)(OH)2 · H2O |
| 9.BE.05 | Itoigawaite | SrAl2(Si2O7)(OH)2 · H2O |
| 9.BE.07 | Ilvaite | CaFe3+Fe2+2(Si2O7)O(OH) |
| 9.BE.07 | Amamoorite | CaMn2+2Mn3+(Si2O7)O(OH) |
| 9.BE.07 | Manganilvaite | CaFe2+Fe3+Mn2+(Si2O7)O(OH) |
| 9.BE.10 | Suolunite | Ca2(H2Si2O7) · H2O |
| 9.BE.12 | Jaffeite | Ca6(Si2O7)(OH)6 |
| 9.BE.15 | Fresnoite | Ba2Ti(Si2O7)O |
| 9.BE.17 | Janhaugite | (Na,Ca)3(Mn2+,Fe2+)3(Ti,Zr,Nb)2(Si2O7)2O2(OH,F)2 |
| 9.BE.17 | Burpalite | Na2CaZr(Si2O7)F2 |
| 9.BE.17 | Niocalite | (Ca,Nb)4(Si2O7)(O,OH,F)2 |
| 9.BE.17 | Normandite | NaCa(Mn,Fe)(Ti,Nb,Zr)(Si2O7)OF |
| 9.BE.17 | Hiortdahlite | Na2Ca4(Ca0.5Zr0.5)Zr(Si2O7)2OF3 |
| 9.BE.17 | Låvenite | Na2Ca2Mn2Zr2(Si2O7)2O2F2 |
| 9.BE.17 | Cuspidine | Ca8(Si2O7)2F4 |
| 9.BE.17 | Wöhlerite | Na2Ca4ZrNb(Si2O7)2O3F |
| 9.BE.17 | Baghdadite | Ca6Zr2(Si2O7)2O4 |
| 9.BE.20 | Nacareniobsite-(Ce) | Na3Ca3(Ce,REE)Nb(Si2O7)2OF3 |
| 9.BE.20 | Roumaite | (Ca,Na,REE,◻)7(Nb,Ti)[Si2O7]2OF3 |
| 9.BE.20 | Rinkite-(Ce) | (Ca3Ce)Na(NaCa)Ti(Si2O7)2(OF)F2 |
| 9.BE.20 | Nacareniobsite-(Nd) | Ca2(CaNd)Na3Nb(Si2O7)2(OF)F2 |
| 9.BE.20 | Rinkite-(Y) | Na2Ca4YTi(Si2O7)2OF3 |
| 9.BE.20 | Mosandrite-(Ce) | (Ca3REE)[(H2O)2Ca0.5◻0.5]Ti(Si2O7)2(OH)2(H2O)2 |
| 9.BE.22 | Hainite-(Y) | Na2Ca4(Y,REE)Ti(Si2O7)2OF3 |
| 9.BE.22 | Rosenbuschite | Na6Ca6Zr3Ti(Si2O7)4O2F6 |
| 9.BE.22 | Götzenite | NaCa6Ti(Si2O7)2OF3 |
| 9.BE.22 | Fogoite-(Y) | Na3Ca2Y2Ti(Si2O7)2OF3 |
| 9.BE.22 | Kochite | Na3Ca2MnZrTi(Si2O7)2OF3 |
| 9.BE.23 | Dovyrenite | Ca6Zr(Si2O7)2(OH)4 |
| 9.BE.25 | Lamprophyllite | (Na,Mn2+)3(Sr,Na)2(Ti,Fe3+)3(Si2O7)2O2(OH,O,F)2 |
| 9.BE.25 | Seidozerite | Na4MnZr2Ti(Si2O7)2O2F2 |
| 9.BE.25 | Nabalamprophyllite | (BaNa)Ti2Na3Ti(Si2O7)2O2(OH)2 |
| 9.BE.25 | Schüllerite | Ba2Na(Mn,Ca)(Fe3+,Mg,Fe2+)2Ti2(Si2O7)2(O,F)4 |
| 9.BE.25 | Ericssonite | BaMn2+2Fe3+(Si2O7)O(OH) |
| 9.BE.25 | Grenmarite | Na4MnZr3(Si2O7)2O2F2 |
| 9.BE.25 | Kazanskyite | BaNa3Ti2Nb(Si2O7)2O2(OH)2(H2O)4 |
| 9.BE.25 | Saamite | Ba◻Na3Ti2Nb(Si2O7)2O2(OH)F(H2O)2 |
| 9.BE.25 | Emmerichite | Ba2Na(Na,Fe2+)2(Fe3+,Mg)Ti2(Si2O7)2O2F2 |
| 9.BE.25 | Barytolamprophyllite | (Ba,Na)2(Na,Ti,Fe3+)4Ti2(Si2O7)2O(OH,F) |
| 9.BE.25 | 'Ericssonite-2O' | BaMn2+2Fe3+(Si2O7)O(OH) |
| 9.BE.25 | Fluorbarytolamprophyllite | (Ba,Sr)2[(Na,Fe2+)3(Ti,Mg)F2][Ti2(Si2O7)2O2] |
| 9.BE.25 | Fluorlamprophyllite | Na3(SrNa)Ti3(Si2O7)2O2F2 |
| 9.BE.25 | Lileyite | Ba2(Na,Fe,Ca)3MgTi2(Si2O7)2O2F2 |
| 9.BE.27 | Kolskyite | CaNa2Ti4(Si2O7)2O4(H2O)7 |
| 9.BE.27 | Vigrishinite | NaZnTi4(Si2O7)2O3(OH)(H2O)4 |
| 9.BE.27 | Selivanovaite | NaFe3+Ti4(Si2O7)2O4(H2O)4 |
| 9.BE.27 | Murmanite | Na2Ti2(Si2O7)O2 · 2H2O |
| 9.BE.30 | Epistolite | (Na◻)Nb2Na3Ti(Si2O7)2O2(OH)2(H2O)4 |
| 9.BE.32 | Lomonosovite | Na5Ti2(Si2O7)(PO4)O2 |
| 9.BE.35 | Vuonnemite | Na11Ti4+Nb2(Si2O7)2(PO4)2O3(F,OH) |
| 9.BE.37 | Sobolevite | Na13Ca2Mn2Ti3(Si2O7)2(PO4)4O3F3 |
| 9.BE.40 | Ferroinnelite | Ba4Ti2Na(NaFe2+)Ti(Si2O7)2[(SO4)(PO4)]O2[O(OH)] |
| 9.BE.40 | Phosphoinnelite | Na3Ba4Ti3(Si2O7)2(PO4,SO4)2O2F |
| 9.BE.40 | Innelite | Ba4Ti2Na(NaMn2+)Ti(Si2O7)2[(SO4)(PO4)]O2[O(OH)] |
| 9.BE.42 | Yoshimuraite | Ba2Mn2Ti(Si2O7)(PO4)O(OH) |
| 9.BE.42 | Horiite | Ba2Mn2Mn4Ti2(Si2O7)2(PO4)2O2(OH)2 |
| 9.BE.45 | Quadruphite | Na6Na2(CaNa)2Na2Ti2Na2Ti2(Si2O7)2(PO4)4O4F2 |
| 9.BE.47 | Polyphite | Na5(Na4Ca2)Ti2(Si2O7)(PO4)3O2F2 |
| 9.BE.50 | Shkatulkalite | Na2Nb2Na3Ti(Si2O7)2O2(FO)(H2O)4(H2O)3 |
| 9.BE.50 | Bornemanite | Na6BaTi2Nb(Si2O7)2(PO4)O2(OH)F |
| 9.BE.55 | Hejtmanite | Ba2Mn2+4Ti2(Si2O7)2O2(OH)2F2 |
| 9.BE.55 | Bykovaite | (Ba,Na,K)2(Na,Ti,Mn)4(Ti,Nb)2(Si2O7)2O2(H2O,F,OH)2 · 3.5H2O |
| 9.BE.55 | Nechelyustovite | (Ba,Sr,K)2(Na,Ti,Mn)4(Ti,Nb)2(Si2O7)2O2(O,H2O,F)2 · 4.5H2O |
| 9.BE.55 | Bafertisite | Ba2Fe2+4Ti2(Si2O7)2O2(OH)2F2 |
| 9.BE.60 | Delindeite | (Na,K)2(Ba,Ca)2(Ti,Fe,Al)3(Si2O7)2O2(OH)2 · 2H2O |
| 9.BE.62 | 'Orthochevkinite' | (Ce,La,Ca,Na,Th)4(Fe2+,Mg)2(Ti,Fe3+)3Si4O22 |
| 9.BE.62 va | 'Strontium Perrierite' | (Ce,Sr,La,Ca)4Fe2+(Ti,Zr,Fe)2Ti2(Si2O7)2O8 |
| 9.BE.62 | 'Chevkinite-(Nd)' | (Nd,REE)4(Fe2+,Mg)(Fe2+,Ti,Fe3+)2(Ti,Fe3+)2(Si2O7)2O8 ? |
| 9.BE.62 | 'Perrierite-(Nd)' | Nd4MgFe3+2Ti2(Si2O7)2O8 ? |
| 9.BE.65 | Bussenite | Na2Ba2Fe2+Ti(Si2O7)(CO3)(OH)3F |
| 9.BE.67 | Jinshajiangite | BaNaFe2+4Ti2(Si2O7)2O2(OH)2F |
| 9.BE.67 | Perraultite | BaNaMn2+4Ti2(Si2O7)2O2(OH)2F |
| 9.BE.70 | Dingdaohengite-(Ce) | (Ce,La)4Fe2+(Ti,Fe2+,Mg,Fe3+)2Ti2(Si2O7)2O8 |
| 9.BE.70 | Perrierite-(Ce) | Ce4MgFe3+2Ti2(Si2O7)2O8 |
| 9.BE.70 | Karnasurtite-(Ce) | (Ce,La,Th)(Ti,Nb)(Al,Fe)(Si2O7)(OH)4 · 3H2O |
| 9.BE.70 | Maoniupingite-(Ce) | (Ce,Ca)4(Fe3+,Ti,Fe2+,◻)(Ti,Fe3+,Fe2+,Nb)4(Si2O7)2O8 |
| 9.BE.70 | Matsubaraite | Sr4Ti5(Si2O7)2O8 |
| 9.BE.70 | Rengeite | Sr4ZrTi4(Si2O7)2O8 |
| 9.BE.70 | Polyakovite-(Ce) | (Ce,Ca)4(Mg,Fe2+)(Cr3+,Fe3+)2(Ti,Nb)2(Si2O7)2O8 |
| 9.BE.70 | Hezuolinite | (Sr,REE)4Zr(Ti,Fe3+)4(Si2O7)2O8 |
| 9.BE.70 | 'UM2008-53-SiO:SrTiZr' | Sr4ZrTi4(Si2O7)2O8 |
| 9.BE.70 | Chevkinite-(Ce) | Ce4(Ti,Fe2+,Fe3+)5O8(Si2O7)2 |
| 9.BE.70 | Perrierite-(La) | (La,Ce,Ca)4(Fe2+,Mn)(Ti,Fe3+,Al)4[(Si2O7)O4]2 |
| 9.BE.70 | Strontiochevkinite | (Sr,La,Ce,Ca)4Fe2+(Ti,Zr)2Ti2(Si2O7)2O8 |
| 9.BE.72 | Fersmanite | Ca4(Na,Ca)4(Ti,Nb)4(Si2O7)2O8F3 |
| 9.BE.75 | Belkovite | Ba3(Nb,Ti)6(Si2O7)2O12 |
| 9.BE.77 | Nasonite | Pb6Ca4(Si2O7)3Cl2 |
| 9.BE.80 | Melanotekite | Pb2Fe3+2(Si2O7)O2 |
| 9.BE.80 | Kentrolite | Pb2Mn3+2(Si2O7)O2 |
| 9.BE.82 | Alexkuznetsovite-(La) | La2Mn(CO3)(Si2O7) |
| 9.BE.82 | Tilleyite | Ca5(Si2O7)(CO3)2 |
| 9.BE.85 | Killalaite | Ca6.4(H0.6Si2O7)2(OH)2 |
| 9.BE.87 | Stavelotite-(La) | (La,Nd,Ca)3Mn2+3Cu(Mn3+,Fe3+,Mn4+)26(Si2O7)6O30 |
| 9.BE.90 | Magnesiorowlandite-(Y) | Y4(Mg,Fe)(Si2O7)2F2 |
| 9.BE.92 | Cervandonite-(Ce) | (Ce,Nd,La)(Fe3+,Fe2+,Ti,Al)3O2(Si2O7)(As3+O3)(OH) |
| 9.BE.92 | Chirvinskyite | (Na,Ca)13(Fe,Mn,◻)2(Ti,Zr)5(Si2O7)4(OH,O)12 · 2H2O |
| 9.BE.95 | Rusinovite | Ca10(Si2O7)3Cl2 |
| 9.BE.95 | Batisivite | BaV3+8Ti6(Si2O7)O22 |
| 9.BE.97 | Schlüterite-(Y) | (Y,REE)2AlSi2O7(OH)2F |
Other Information
Notes:
Soluble in strong acids like HCl and HNO3.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Biraite-(Ce)
mindat.org URL:
https://www.mindat.org/min-27384.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Biraite-(Ce)
Reference List:
Konev, Alexey, Pasero, Marco, Pushcharovsky, Dmitry, Merlino, Stefano, Kashaev, Anvar, Suvorova, Ludmila, Ushchapovskaya, Zinaida, Nartova, Nadezda, Lebedeva, Yulia, Chukanov, Nikita (2005) Biraite-(Ce), Ce2Fe2+(CO3)(Si2O7), a new mineral from Siberia with a novel structure type. European Journal of Mineralogy, 17 (5) 715-721 doi:10.1127/0935-1221/2005/0017-0715
Localities for Biraite-(Ce)
Showing 4 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Russia | |
| webmineral.ru (2020) +1 other reference |
| Koneva A.A. et al. (2010) |
| Konev et al. (2005) |
USA | |
| Gammons et al. (2024) |
Quick NavTopAbout Biraite-(Ce)Unique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Ust'-Biraya, Biraya Fe-REE ore occurrence, Biraya and Bya Rivers confluence area, Vitim Plateau, Irkutsk Oblast, Russia