Bearthite
A valid IMA mineral species
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About Bearthite
Peter Bearth
Formula:
Ca2Al(PO4)2(OH)
Colour:
Pale yellow
Hardness:
4 - 5
Specific Gravity:
3.25 (Calculated)
Crystal System:
Monoclinic
Member of:
Name:
Named in honor of Peter Bearth (30 August 1902, Sumvitg, Switzerland - 24 August 1989, Basel, Switzerland) in recognition of his pioneering petrographic work on the high-pressure terranes of the western Alps. He mapped 1100 km2 of alpine and high alpine terrain in Oberwald. He was simultaneously a high school teacher and a professor of Petrography at the University of Basel.
This page provides mineralogical data about Bearthite.
Unique Identifiers
Mindat ID:
590
Long-form identifier:
mindat:1:1:590:4
Similar Names
| Barthite | A synonym of 'Copper-bearing Austinite' |
IMA Classification of Bearthite
Approved
IMA Formula:
Ca2Al(PO4)2OH
Approval year:
1986
First published:
1993
Classification of Bearthite
8.BG.05
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
G : With medium-sized and large cations, (OH, etc.):RO4 = 0.5:1
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
G : With medium-sized and large cations, (OH, etc.):RO4 = 0.5:1
41.10.4.2
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
10 : (AB)3(XO4)2Zq
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
10 : (AB)3(XO4)2Zq
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 |
|---|---|---|
| Bth | 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 Bearthite
Transparency:
Transparent
Colour:
Pale yellow
Streak:
White
Hardness:
4 - 5 on Mohs scale
Cleavage:
Poor/Indistinct
One poor prismatic cleavage.
One poor prismatic cleavage.
Fracture:
Irregular/Uneven
Density:
3.25 g/cm3 (Calculated)
Optical Data of Bearthite
Type:
Biaxial (+)
RI values:
nα = 1.662(1) nβ = 1.671(1) nγ = 1.696(1)
2V:
Measured: 65° , Calculated: 64°
Max. Birefringence:
δ = 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:
Moderate
Dispersion:
Weak to distint, r
Optical Extinction:
X = b.
Chemistry of Bearthite
Mindat Formula:
Ca2Al(PO4)2(OH)
Element Weights:
Common Impurities:
Sr,Mg,Fe,Ce,La,Si,F,Cl,Nd
Crystallography of Bearthite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Cell Parameters:
a = 7.23 Å, b = 5.73 Å, c = 8.26 Å
β = 112.57°
β = 112.57°
Ratio:
a:b:c = 1.262 : 1 : 1.442
Unit Cell V:
315.99 ų (Calculated from Unit Cell)
Z:
2
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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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) |
|---|---|---|---|---|---|---|---|
| 0015407 | Bearthite | Chopin C, Brunet F, Gebert W, Medenbach O, Tillmanns E (1993) Bearthite, Ca2Al[PO4]2(OH), a new mineral from high-pressure terranes of the western Alps Schweizerische Mineralogische und Petrographische Mitteilungen 73 1-9 | 1993 | Dora Maira massif, western Alps, Italy | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.05 Å | (100) |
| 2.867 Å | (61) |
| 2.568 Å | (39) |
| 2.754 Å | (27) |
| 4.58 Å | (22) |
| 2.634 Å | (21) |
| 2.444 Å | (19) |
Comments:
calculated due to poor Gandolphi pattern
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 39 : High-? metamorphism (blueschist, eclogite, ultrahigh ? facies) | |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) |
Type Occurrence of Bearthite
Co-Type Localities:
General Appearance of Type Material:
Yellowish aggregates, up to millimeter size, of partly euhedral, flat prismatic crystals and as smaller anhedral grains corroded by lazulite .
Place of Conservation of Type Material:
Mineralogic-Petrographic Institute, University of Basel, Basel, Switzerland; PB100f.
National School of Mines, Paris, France; 84DM54, 85DM45, 85DM70.
National History Museum, Paris, France.
National School of Mines, Paris, France; 84DM54, 85DM45, 85DM70.
National History Museum, Paris, France.
Geological Setting of Type Material:
In gneiss and schist, in pyrope-phengite quartzite and in coesite-bearing metapelite. Formed through high-pressure metamorphism.
Synonyms of Bearthite
Other Language Names for Bearthite
Relationship of Bearthite to other Species
Member of:
Other Members of Brackebuschite Supergroup:
| Aldomarinoite | Sr2Mn3+(AsO4)2(OH) | Mon. 2/m : P21/m |
| Arsenbrackebuschite | Pb2Fe3+(AsO4)2(OH) | Mon. 2/m : P2/m |
| Arsentsumebite | Pb2Cu(AsO4)(SO4)(OH) | Mon. 2/m : P21/m |
| Brackebuschite | Pb2Mn3+(VO4)2(OH) | Mon. 2/m : P21/m |
| Bushmakinite | Pb2Al(PO4)(VO4)(OH) | Mon. 2/m : P21/m |
| Calderónite | Pb2Fe3+(VO4)2(OH) | Mon. 2/m : P21/m |
| Canosioite | Ba2Fe3+(AsO4)2(OH) | Mon. 2/m : P21/m |
| Feinglosite | Pb2Zn(AsO4)2 · H2O | Mon. 2/m |
| Ferribushmakinite | Pb2Fe3+(PO4)(VO4)(OH) | Mon. 2/m : P21/m |
| Gamagarite | Ba2Fe3+(VO4)2(OH) | Mon. 2/m : P21/m |
| Goedkenite | Sr2Al(PO4)2(OH) | Mon. 2/m : P21/m |
| Grandaite | Sr2Al(AsO4)2(OH) | Mon. 2/m : P21/m |
| Lombardoite | Ba2Mn3+(AsO4)2(OH) | Mon. 2/m : P21/m |
| Tokyoite | Ba2Mn3+(VO4)2(OH) | Mon. 2/m : P21/m |
| Tsumebite | Pb2Cu(PO4)(SO4)(OH) | Mon. 2/m : P21/m |
| 'Unnamed (possible ordered As-analogue of Tokyoite)' | Ba2Mn[(As,V)O4]2(OH) | Mon. 2/m : P21/m |
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 8.BG. | Aldomarinoite | Sr2Mn3+(AsO4)2(OH) |
| 8.BG. | Dongchuanite | Pb4ZnZn2(PO4)4(OH)2 |
| 8.BG. | Cuprodongchuanite | Pb4CuZn2(PO4)4(OH)2 |
| 8.BG. | Canosioite | Ba2Fe3+(AsO4)2(OH) |
| 8.BG.05 | Feinglosite | Pb2Zn(AsO4)2 · H2O |
| 8.BG.05 | Tokyoite | Ba2Mn3+(VO4)2(OH) |
| 8.BG.05 | Lombardoite | Ba2Mn3+(AsO4)2(OH) |
| 8.BG.05 | 'Unnamed (possible ordered As-analogue of Tokyoite)' | Ba2Mn[(As,V)O4]2(OH) |
| 8.BG.05 | Gamagarite | Ba2Fe3+(VO4)2(OH) |
| 8.BG.05 | Arsentsumebite | Pb2Cu(AsO4)(SO4)(OH) |
| 8.BG.05 | 'UM1994-19-PO:CuHMoPb' | Pb2Cu(PO4)(MoO4,AsO4,CrO4,GaO4)(OH) |
| 8.BG.05 | Ferribushmakinite | Pb2Fe3+(PO4)(VO4)(OH) |
| 8.BG.05 | Arsenbrackebuschite | Pb2Fe3+(AsO4)2(OH) |
| 8.BG.05 | Goedkenite | Sr2Al(PO4)2(OH) |
| 8.BG.05 | Tsumebite | Pb2Cu(PO4)(SO4)(OH) |
| 8.BG.05 | Brackebuschite | Pb2Mn3+(VO4)2(OH) |
| 8.BG.05 | Bushmakinite | Pb2Al(PO4)(VO4)(OH) |
| 8.BG.05 | Calderónite | Pb2Fe3+(VO4)2(OH) |
| 8.BG.10 | Mélonjosephite | CaFe2+Fe3+(PO4)2(OH) |
| 8.BG.15 | Tancoite | LiNa2Al(PO4)(PO3OH)(OH) |
| 8.BG.20 | Dmisokolovite | K3Cu5AlO2(AsO4)4 |
| 8.BG.25 | Shchurovskyite | K2CaCu6O2(AsO4)4 |
| 8.BG.30 | Wrightite | K2Al2O(AsO4)2 |
| 8.BG.35 | Polyarsite | Na7CaMgCu2(AsO4)4F2Cl |
Fluorescence of Bearthite
cathode luminescence - green
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 Bearthite
mindat.org URL:
https://www.mindat.org/min-590.html
Please feel free to link to this page.
Please feel free to link to this page.
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Mineral Dealers:
References for Bearthite
Reference List:
Jambor, John L., Vanko, David A. (1993) New Mineral Names. American Mineralogist, 78 (11-12) 1314-1319
Localities for Bearthite
Showing 11 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.
Austria | |
| SEM-EDS and XRD on sample AN1267 (HK022) |
| Bernhard (1998) | |
| Bernhard (2006) |
Italy (TL) | |
| Chopin C et al. (1993) +1 other reference |
| Mandarino (1996) | |
| Piccoli et al. (2007) |
| Chopin C et al. (1993) | |
| Morteani et al. (1996) |
| Folie et al. (2010) | |
Sweden | |
| Sandström (2007) |
Switzerland (TL) | |
| SMPM 73 (1993) +3 other references |
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Ganz valley, Langenwang, Bruck-Mürzzuschlag District, Styria, Austria