Fedorovskite
A valid IMA mineral species
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About Fedorovskite
Formula:
Ca2Mg2B4O7(OH)6
Colour:
Brown
Lustre:
Vitreous
Hardness:
4½
Specific Gravity:
2.65
Crystal System:
Orthorhombic
Name:
Named for Nikolai Mikhailovich Fedorovskii (1886-1956), Russian crystallographer, mineralogist and founder of the Russian Research Institute of Mineral Resources, Moscow, Russia.
Unique Identifiers
Mindat ID:
1468
Long-form identifier:
mindat:1:1:1468:3
IMA Classification of Fedorovskite
Approved
Approval year:
1975
First published:
1977
Classification of Fedorovskite
6.DA.25
6 : BORATES
D : Tetraborates
A : Neso-tetraborates
6 : BORATES
D : Tetraborates
A : Neso-tetraborates
Dana 7th ed.:
25.4.1.2
25.4.1.2
25 : ANHYDROUS BORATES CONTAINING HYDROXYL OR HALOGEN
4 : Tetraborates
25 : ANHYDROUS BORATES CONTAINING HYDROXYL OR HALOGEN
4 : Tetraborates
9.4.2
9 : Borates
4 : Borates of Ca and Mn
9 : Borates
4 : Borates of Ca and Mn
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 |
|---|---|---|
| Fdo | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Fedorovskite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Fedorovskite
Vitreous
Transparency:
Translucent
Colour:
Brown
Streak:
Pale brown
Hardness:
4½ on Mohs scale
Cleavage:
Perfect
Perfect on {100}
Perfect on {100}
Density:
2.65 g/cm3 (Measured) 2.60 g/cm3 (Calculated)
Optical Data of Fedorovskite
Type:
Biaxial (-)
RI values:
nα = 1.619 - 1.623 nβ = 1.627 - 1.632 nγ = 1.629 - 1.634
2V:
Measured: 48°
Max. Birefringence:
δ = 0.010 - 0.011
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
Pleochroism:
Visible
Comments:
X= colorless to pale yellow
Z= yellow to bright yellow
Z= yellow to bright yellow
Chemistry of Fedorovskite
Mindat Formula:
Ca2Mg2B4O7(OH)6
Element Weights:
Crystallography of Fedorovskite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pbam
Cell Parameters:
a = 8.96(2) Å, b = 13.15(2) Å, c = 8.15(1) Å
Ratio:
a:b:c = 0.681 : 1 : 0.62
Unit Cell V:
960.27 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Prismatic crystals, with rhombic outlines, fibrous aggregates.
Twinning:
Polysynthetic, composition plane {100}
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.92 Å | (100) |
| 3.02 Å | (70) |
| 2.59 Å | (100) |
| 2.28 Å | (60) |
| 2.119 Å | (70) |
| 1.693 Å | (70) |
| 1.630 Å | (70) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations |
Geological Setting:
Skarn type boron deposit.
Type Occurrence of Fedorovskite
General Appearance of Type Material:
Mono-mineral veinlets, commonly fibrous
Place of Conservation of Type Material:
A. E. Fersman Mineralogical Museum, Academy of Science, Moscow, Russia.
Associated Minerals at Type Locality:
Synonyms of Fedorovskite
Other Language Names for Fedorovskite
Relationship of Fedorovskite to other Species
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 3 photos of Fedorovskite associated with Kurchatovite | Ca(Mg,Mn2+)[B2O5] |
| 2 photos of Fedorovskite associated with Ludwigite | Mg2Fe3+(BO3)O2 |
| 1 photo of Fedorovskite associated with Borcarite | Ca4Mg(B4O6(OH)6)(CO3)2 |
| 1 photo of Fedorovskite associated with Roweite | Ca2Mn2+2B4O7(OH)6 |
| 1 photo of Fedorovskite associated with Frolovite | Ca[B(OH)4]2 |
| 1 photo of Fedorovskite associated with Szaibélyite | MgBO2(OH) |
Related Minerals - Strunz-mindat Grouping
| 6.DA.10 | Borax | Na2(B4O5)(OH)4 · 8H2O |
| 6.DA.15 | Tincalconite | Na2(B4O7) · 5H2O |
| 6.DA.20 | Hungchaoite | Mg(B4O7) · 9H2O |
| 6.DA.25 | Roweite | Ca2Mn2+2B4O7(OH)6 |
| 6.DA.30 | Hydrochlorborite | Ca4B8O15Cl2 · 21H2O |
| 6.DA.35 | Uralborite | Ca2[B3O3(OH)5 · OB(OH)3] |
| 6.DA.40 | Numanoite | Ca4Cu(B4O6(OH)6)(CO3)2 |
| 6.DA.40 | Borcarite | Ca4Mg(B4O6(OH)6)(CO3)2 |
| 6.DA.60 | Fontarnauite | (Na,K)2(Sr,Ca)(SO4)[B5O8(OH)] · 2H2O |
Other Information
Notes:
Insoluble in H2O, dissolved by dilute HCl
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 Fedorovskite
mindat.org URL:
https://www.mindat.org/min-1468.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Fedorovskite
Localities for Fedorovskite
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.
Japan | |
| Kobayashi et al. (2020) |
Mexico | |
| Christopher Emproto |
| Carnegie Museum of Natural History ... +1 other reference | |
Russia (TL) | |
| Malinko et al. (1972) +2 other references |
Quick NavTopAbout FedorovskiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPronunciation Physical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Solongo B deposit, Ozernoe ore cluster, Yeravninsky District, Buryatia, Russia