Bulachite
A valid IMA mineral species
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About Bulachite
Neubulach, Germany
Formula:
Al6(AsO4)3(OH)9(H2O)4 · 2H2O
Originally assumed be Al2(AsO4)(OH)3 · 3H2O.
Colour:
White to blue-green
Hardness:
2
Specific Gravity:
2.60
Crystal System:
Orthorhombic
Name:
Named for the type locality at Neubulach, Baden Württemberg, Germany.
A rare secondary Al arsenate hydrate.
Grey et al. (2020) show that bulachite from Cap Garonne has the formula Al6(AsO4)3(OH)9(H2O)4⋅2H2O and is intergrown with a higher hydrate with composition Al6(AsO4)3(OH)9(H2O)4⋅8H2O. The latter was later named galeaclolusite.
Grey et al. (2020) show that bulachite from Cap Garonne has the formula Al6(AsO4)3(OH)9(H2O)4⋅2H2O and is intergrown with a higher hydrate with composition Al6(AsO4)3(OH)9(H2O)4⋅8H2O. The latter was later named galeaclolusite.
Unique Identifiers
Mindat ID:
799
Long-form identifier:
mindat:1:1:799:3
IMA Classification of Bulachite
Approved
IMA Formula:
Al6(As5+O4)3(OH)9(H2O)4·2H2O
Approval year:
1982
First published:
1983
Classification of Bulachite
8.DE.15
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
E : With only medium-sized cations, (OH, etc.):RO4 = 3:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
E : With only medium-sized cations, (OH, etc.):RO4 = 3:1
42.6.7.2
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
6 : A2(XO4)Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
6 : A2(XO4)Zq·xH2O
20.4.2
20 : Arsenates (also arsenates with phosphate, but without other anions)
4 : Arsenates of Group III metals (Al, rare earths)
20 : Arsenates (also arsenates with phosphate, but without other anions)
4 : Arsenates of Group III metals (Al, rare earths)
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 |
|---|---|---|
| Buh | 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 Bulachite
Transparency:
Translucent
Comment:
Lustre is Satiny
Colour:
White to blue-green
Streak:
White
Hardness:
2 on Mohs scale
Cleavage:
None Observed
Density:
2.60 g/cm3 (Measured) 2.55 g/cm3 (Calculated)
Optical Data of Bulachite
Type:
Biaxial (-)
RI values:
nα = 1.54 nβ = 1.546 nγ = 1.548
2V:
Measured: 66° , Calculated: 58°
Max. Birefringence:
δ = 0.008
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
Chemistry of Bulachite
Mindat Formula:
Al6(AsO4)3(OH)9(H2O)4 · 2H2O
Originally assumed be Al2(AsO4)(OH)3 · 3H2O.
Originally assumed be Al2(AsO4)(OH)3 · 3H2O.
Element Weights:
Elements listed:
Crystallography of Bulachite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnma
Cell Parameters:
a = 15.3994(3) Å, b = 17.6598(3) Å, c = 7.8083(1) Å
Ratio:
a:b:c = 0.872 : 1 : 0.442
Unit Cell V:
2,123.47 ų (Calculated from Unit Cell)
Comment:
Cell from Grey et al. (2020). Cell of type material: a = 15.53, b = 17.78, c = 7.03 Å.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.78 Å | (100) |
| 3.49 Å | (80) |
| 8.97 Å | (70) |
| 6.55 Å | (70) |
| 5.92 Å | (70) |
| 3.75 Å | (70) |
| 2.73 Å | (60) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Bulachite
General Appearance of Type Material:
Exceedingly fine-grained needles in radial
aggregates encrusting quartz
aggregates encrusting quartz
Place of Conservation of Type Material:
Institut für Mineralogie und Kristallchemie, Universität Stuttgart, Stuttgart, Germany, numbers BU1,27.
Associated Minerals at Type Locality:
Synonyms of Bulachite
Other Language Names for Bulachite
Common Associates
Associations Based on Photo Data:
| 2 photos of Bulachite associated with Goethite | Fe3+O(OH) |
| 1 photo of Bulachite associated with Azurite | Cu3(CO3)2(OH)2 |
| 1 photo of Bulachite associated with Malachite | Cu2(CO3)(OH)2 |
| 1 photo of Bulachite associated with Bariopharmacoalumite | Ba0.5Al4(AsO4)3(OH)4 · 4H2O |
| 1 photo of Bulachite associated with Mansfieldite | AlAsO4 · 2H2O |
Related Minerals - Strunz-mindat Grouping
| 8.DE. | Arsenoveszelyite | Cu2Zn(AsO4)(OH)3 · 2H2O |
| 8.DE. | Kipushite | (Cu,Zn)5Zn(PO4)2(OH)6 · H2O |
| 8.DE. | Goldhillite | Cu5Zn(AsO4)2(OH)6 · H2O |
| 8.DE.05 | Senegalite | Al2(PO4)(OH)(OH)2 · H2O |
| 8.DE.10 | Fluellite | Al2(PO4)F2(OH) · 7H2O |
| 8.DE.20 | Zapatalite | Cu3Al4(PO4)3(OH)9 · 4H2O |
| 8.DE.25 | Ceruleite | Cu2Al7(AsO4)4(OH)13 · 11.5H2O |
| 8.DE.30 | Veszelyite | (Cu,Zn)2Zn(PO4)(OH)3 · 2H2O |
| 8.DE.35 | Philipsburgite | Cu5Zn(AsO4)(PO4)(OH)6 · H2O |
| 8.DE.40 | Juanitaite | (Cu,Ca,Fe)10Bi(AsO4)4(OH)11 · 2H2O |
| 8.DE.45 | Iangreyite | Ca2Al7(PO4)2(PO3OH)2(OH,F)15 · 8H2O |
Other Information
Notes:
Easily soluble in HCl (1:1),less easily in HNO3 (1:1)
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 Bulachite
mindat.org URL:
https://www.mindat.org/min-799.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Bulachite
Reference List:
Fleischer, M.; Mandarino, J.A.; Pabst, A. (1980) New mineral names. American Mineralogist, 65 (1-2). 205-210
Dunn, Pete J., Chao, George Y., Fleischer, Michael, Ferraiolo, James A., Langley, Richard H., Pabst, Adolf, Zilczer, Janet A. (1985) New mineral names. American Mineralogist, 70 (1-2) 214-221
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., Nichols, Monte C. - Eds. (2016) Handbook of Mineralogy. https://www.handbookofmineralogy.org/
Grey, Ian E., Yoruk, Emre, Kodjikian, Stéphanie, Klein, Holger, Bougerol, Catherine, Brand, Helen E.A., Bordet, Pierre, Mumme, William G., Favreau, Georges, Mills, Stuart J. (2020) Bulachite, [Al6(AsO4)3(OH)9(H2O)4]⋅2H2O from Cap Garonne, France: Crystal structure and formation from a higher hydrate. Mineralogical Magazine, 84 (4) 608-615 doi:10.1180/mgm.2020.52
Localities for Bulachite
Showing 7 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.
France | |
| Favreau et al. (2014) +2 other references |
| Favreau et al. (2024) | |
Germany (TL) | |
| Walenta (1983) +1 other reference |
| Weiß (1990) |
Greece | |
| Schusser et al. (2022) |
Italy | |
| Frau et al. (2001) |
UK | |
| collections.museumvictoria.com.au (n.d.) +1 other reference |
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Cap Garonne Mine, Le Pradet, Toulon, Var, Provence-Alpes-Côte d'Azur, France