Bergslagite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Bergslagite
Formula:
CaBeAsO4(OH)
Colour:
Colourless, white, grey, dark grey-brown, brownish black, green, pink
Lustre:
Vitreous, Greasy
Hardness:
5
Specific Gravity:
3.4
Crystal System:
Monoclinic
Member of:
Name:
For its occurrence at Långban, which is in the Bergslagen region of Sweden.
This page provides mineralogical data about Bergslagite.
Unique Identifiers
Mindat ID:
632
Long-form identifier:
mindat:1:1:632:9
IMA Classification of Bergslagite
Classification of Bergslagite
8.BA.10
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
A : With small and medium-sized cations
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
A : With small and medium-sized cations
41.5.4.4
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
5 : (AB)2(XO4)Zq
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
5 : (AB)2(XO4)Zq
20.2.16
20 : Arsenates (also arsenates with phosphate, but without other anions)
2 : Arsenates of Be, Mg, Ca or Ba
20 : Arsenates (also arsenates with phosphate, but without other anions)
2 : Arsenates of Be, Mg, Ca or Ba
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 |
|---|---|---|
| Bgl | 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 Bergslagite
Vitreous, Greasy
Transparency:
Translucent
Colour:
Colourless, white, grey, dark grey-brown, brownish black, green, pink
Hardness:
5 on Mohs scale
Fracture:
Irregular/Uneven
Density:
3.4 g/cm3 (Measured) 3.4 g/cm3 (Calculated)
Optical Data of Bergslagite
Type:
Biaxial (-)
RI values:
nα = 1.659 - 1.66 nβ = 1.678 - 1.681 nγ = 1.69 - 1.694
2V:
Measured: 70° , Calculated: 74° to 78°
Max. Birefringence:
δ = 0.031 - 0.034
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:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r >> v
Chemistry of Bergslagite
Mindat Formula:
CaBeAsO4(OH)
Element Weights:
Common Impurities:
Si
Crystallography of Bergslagite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 4.88 Å, b = 7.8 Å, c = 10.12 Å
β = 90.16°
β = 90.16°
Ratio:
a:b:c = 0.626 : 1 : 1.297
Unit Cell V:
385.21 ų (Calculated from Unit Cell)
Z:
4
Morphology:
elongated flattened crystals to 1 cm; crusts
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0010863 | Bergslagite | Hansen S, Falth L, Johnson O (1984) Bergslagite, a mineral with tetrahedral berylloarsenate sheet anions Zeitschrift fur Kristallographie 166 73-80 |  | 1984 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.200 Å | (10) |
| 3.519 Å | (8) |
| 4.879 Å | (7) |
| 3.905 Å | (7) |
| 3.046 Å | (7) |
| 2.917 Å | (7) |
| 2.409 Å | (6) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4a: Earth’s earliest continental crust | >4.4-3.0 |
| 20 : Acidic volcanic rocks | |
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
| Stage 7: Great Oxidation Event | <2.4 |
| 46 : Near-surface hydrothermal alteration of minerals (see also #22) |
Type Occurrence of Bergslagite
General Appearance of Type Material:
As thin veinlets in hematite ore
Place of Conservation of Type Material:
University of Copenhagen, Copenhagen, Denmark
National Museum of National History, Washington D.C., USA; 162582
National Museum of National History, Washington D.C., USA; 162582
Associated Minerals at Type Locality:
Synonyms of Bergslagite
Other Language Names for Bergslagite
Relationship of Bergslagite to other Species
Member of:
Other Members of Herderite Subgroup:
| Herderite | CaBe(PO4)F | Mon. 2/m |
| Hydroxylherderite | CaBe(PO4)(OH) | Mon. 2/m : P21/b |
Common Associates
Associations Based on Photo Data:
| 11 photos of Bergslagite associated with Hematite | Fe2O3 |
| 5 photos of Bergslagite associated with Tilasite | CaMg(AsO4)F |
| 4 photos of Bergslagite associated with Calcite | CaCO3 |
| 3 photos of Bergslagite associated with Quartz | SiO2 |
| 2 photos of Bergslagite associated with Svabite | Ca5(AsO4)3F |
| 2 photos of Bergslagite associated with Berzeliite | (NaCa2)Mg2(AsO4)3 |
| 2 photos of Bergslagite associated with Hydroxylherderite | CaBe(PO4)(OH) |
| 1 photo of Bergslagite associated with Wallkilldellite | Ca2Mn2+3(AsO4)2(OH)4 · 9H2O |
Related Minerals - Strunz-mindat Grouping
| 8.BA. | Vladkuzminite | K4CuZn3(AsO4)4 |
| 8.BA. | Axelite | Na14Cu7(AsO4)8F2Cl2 |
| 8.BA. | Elramlyite-(Ce) | (◻0.67Ce0.33)Th2(PO4)2F3 |
| 8.BA. | Tomcampbellite | [KCl][Fe2+14(OH)6(PO4)6(PO3OH)2] |
| 8.BA.05 | Väyrynenite | BeMn2+(PO4)(OH) |
| 8.BA.10 | Herderite | CaBe(PO4)F |
| 8.BA.10 | Hydroxylherderite | CaBe(PO4)(OH) |
| 8.BA.15 | Babefphite | BaBePO4(F,OH) |
Fluorescence of Bergslagite
SW-UV: pale shades of yellowish brown, greenish or bluish
Other Information
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 Bergslagite
mindat.org URL:
https://www.mindat.org/min-632.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 Bergslagite
Reference List:
Hansen, Staffan, Fälth, Lars, Johnsen, Ole (1984) Bergslagite, a mineral with tetrahedral berylloarsenate sheet anions. Zeitschrift für Kristallographie - Crystalline Materials, 166 (14). 73-80 doi:10.1524/zkri.1984.166.14.73
Dunn, Pete J., Gobel, Volker, Grice, Joel D., Puziewicz, Jacek, Shigley, James E., Vanko, David A., Zilczer, Janet (1985) New mineral names. American Mineralogist, 70 (3-4) 436-441
Jambor, John L., Vanko, David A. (1989) New mineral names. American Mineralogist, 74 (7-8) 946-951 p.951
Bačík, Peter, Miyawaki, Ritsuro, Atencio, Daniel, Cámara, Fernando, Fridrichová, Jana (2017) Nomenclature of the gadolinite supergroup. European Journal of Mineralogy, 29 (6) 1067-1082 doi:10.1127/ejm/2017/0029-2659
Shagova, Anastasiia K., Gorelova, Liudmila A., Vereshchagin, Oleg S., Pankin, Dmitrii V., Kasatkin, Anatoly V. (2025) Thermal stability, low- and high-temperature behavior of bergslagite, a berylloarsenate member of the gadolinite supergroup. Physics and Chemistry of Minerals, 52 (1). doi:10.1007/s00269-025-01311-1
Localities for Bergslagite
Showing 9 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.
Brazil | |
| Knut Edvard Larsen collection # MM-6229 (Ex-Luiz Menezes specimen) +1 other reference |
Germany | |
| Kolitsch (1996) |
Italy | |
| Anthony et al. (2000) |
Norway | |
| Raade et al. (2006) |
Sweden (TL) | |
| Hansen et al. (1984) +2 other references |
Switzerland | |
| Brugger et al. (1999) |
| Weibel et al. (1990) +1 other reference |
| Stalder et al. (1998) |
| Brugger et al. (1999) +1 other reference |
Quick NavTopAbout BergslagiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Tennvatn pegmatite, Sørfold, Nordland, Norway