Magnesioalterite
A valid IMA mineral species
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Malcolm Alter
Formula:
Mg2Fe3+4(SO4)4(C2O4)2(OH)4 · 17H2O
Colour:
yellowish green
Lustre:
Vitreous
Hardness:
1½
Specific Gravity:
2.17
Crystal System:
Monoclinic
Name:
Named for its relationship to alterite. The root name honors long-time Arizona field collector Malcolm Alter.
Type Locality:
Isostructural with:
The Mg analogue of alterite. Elemental combination somewhat similar to that of hauckite which, however, is not an oxalate.
Unique Identifiers
Mindat ID:
55112
Long-form identifier:
mindat:1:1:55112:0
IMA Classification of Magnesioalterite
Approved
IMA Formula:
Mg2Fe3+4(S6+O4)4((C2)6+O4)2(OH)4·17H2O
Approval year:
2020
Type description reference:
Classification of Magnesioalterite
7.DE.
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
E : With only medium-sized cations; unclassified
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
E : With only medium-sized cations; unclassified
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 |
|---|---|---|
| Matr | 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 Magnesioalterite
Vitreous
Transparency:
Transparent
Colour:
Yellowish green
Streak:
White
Hardness:
1½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
(100)
(100)
Parting:
none
Density:
2.17(3) g/cm3 (Measured)
Optical Data of Magnesioalterite
Type:
Biaxial (+)
RI values:
nα = 1.520(5) nβ = 1.578(6) nγ = 1.610(5)
2V:
Measured: 74° (2), Calculated: 76.5°
Birefringence:
Max. Birefringence:
δ = 0.090
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
Chemistry of Magnesioalterite
Mindat Formula:
Mg2Fe3+4(SO4)4(C2O4)2(OH)4 · 17H2O
Element Weights:
Crystallography of Magnesioalterite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 16.766(1) Å, b = 9.4074(7) Å, c = 25.351(3) Å
β = 108.258(5)°
β = 108.258(5)°
Ratio:
a:b:c = 1.782 : 1 : 2.695
Unit Cell V:
3,797.17 ų (Calculated from Unit Cell)
Twinning:
none
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.854 Å | (100) |
| 4.593 Å | (36) |
| 4.377 Å | (46) |
| 4.204 Å | (38) |
| 4.142 Å | (35) |
| 3.914 Å | (34) |
| 3.717 Å | (67) |
| 2.668 Å | (47) |
Reference:
Comments:
From Type Description.
Type Occurrence of Magnesioalterite
Place of Conservation of Type Material:
Type material is deposited in the collections of the University of Arizona Mineral Museum, 1601 E University Blvd, Tucson, AZ 85719, USA, catalogue number 22042 (holotype); the RRUFF Project, deposition number R180015 (cotype)
Geological Setting of Type Material:
carbonaceous petrified wood from an unnamed uranium prospect
Associated Minerals at Type Locality:
Synonyms of Magnesioalterite
Other Language Names for Magnesioalterite
Dutch:Magnesioalteriet
German:Magnesioalterit
Related Minerals - Strunz-mindat Grouping
| 7.DE. | Fabritzite | Zn9(SO4)2(OH)12Cl2 · 6H2O |
| 7.DE. | Cossaite | (Mg0.5,◻)Al6(SO4)6(HSO4)F6 · 36H2O |
| 7.DE. | Downsite | K2(MoO3)3(SO4) · 4H2O |
| 7.DE. | Liangjunite | K2(Mo2O5)(SO4)2 · 3H2O |
| 7.DE.05 | Mangazeite | Al2(SO4)(OH)4 · 3H2O |
| 7.DE.10 | 'UKI-1975-(SO:AlCu)' | (Cu, Al, SO4, H2O) |
| 7.DE.10 | Carbonatecyanotrichite | Cu4Al2(CO3,SO4)(OH)12 · 2H2O |
| 7.DE.10 | Cyanotrichite | Cu4Al2(SO4)(OH)12 · 2H2O |
| 7.DE.15 | Schwertmannite | Fe3+16(OH,SO4)12-13O16 · 10-12H2O |
| 7.DE.20 | Tlalocite | Cu10Zn6(Te6+O4)2(Te4+O3)(OH)25Cl · 27H2O |
| 7.DE.25 | Utahite | MgCu4Zn2Te6+3O14(OH)4 · 6H2O |
| 7.DE.35 | Coquandite | Sb6+xO8+x(SO4)(OH)x(H2O)1- x (x = 0.3) |
| 7.DE.40 | Osakaite | Zn4(SO4)(OH)6 · 5H2O |
| 7.DE.42 | Alterite | Zn2Fe3+4(SO4)4(C2O4)2(OH)4 · 17H2O |
| 7.DE.45 | Barrotite | Cu9Al(HSiO4)2[(SO4)(HAsO4)0.5](OH)12 · 8H2O |
| 7.DE.45 | Wilcoxite | MgAl(SO4)2F · 17H2O |
| 7.DE.47 | Tiberiobardiite | {Cu9Al[SiO3(OH)]2(OH)12(H2O)6}(SO4)1.5 · 10H2O |
| 7.DE.50 | Bouškaite | (MoO2)2O(SO3OH)2(H2O)4 |
| 7.DE.50 | Stanleyite | (V4+O)(SO4) · 6H2O |
| 7.DE.57 | 'Khangalasite' | Fe(SO4)(OH) · 2H2O |
| 7.DE.60 | Hydrobasaluminite | Al4(SO4)(OH)10 · 12-36H2O |
| 7.DE.62 | Volaschioite | Fe4(SO4)O2(OH)6 · 2H2O |
| 7.DE.65 | Zaherite | Al12(SO4)5(OH)26 · 20H2O |
| 7.DE.75 | Camérolaite | Cu6Al3(OH)18(H2O)2[Sb(OH)6](SO4) |
Other Information
Notes:
insoluble in water, but slowly dissolve in hydrochloric acid
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 Magnesioalterite
mindat.org URL:
https://www.mindat.org/min-55112.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Magnesioalterite
Localities for Magnesioalterite
Showing 2 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.
USA (TL) | |
| Miyawaki et al. (2020) |
| PXRD and EDS by Tony Kampf in May +1 other reference |
