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Hartkoppeite
A valid IMA mineral species - pending publication
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About Hartkoppeite
Formula:
Ca4Mn2+Mo6+6As5+4O32(OH)2(H2O)14 · 5H2O
Colour:
colorless
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
2.88
Crystal System:
Triclinic
Name:
After type locality. Hartkoppe is the mountain on which the Fuchs quarry is located.
New structure type
Unique Identifiers
Mindat ID:
498758
Long-form identifier:
mindat:1:1:498758:7
IMA Classification of Hartkoppeite
Approved, Pending publication
IMA Formula:
Ca4Mn2+Mo6+6As5+4O32(OH)2(H2O)14·5H2O
Approval year:
2025
Classification of Hartkoppeite
7.GB.
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
G : Molybdates, Wolframates and Niobates
B : With additional anions and/or H2O
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
G : Molybdates, Wolframates and Niobates
B : With additional anions and/or H2O
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 |
|---|---|---|
| Hkp | 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 Hartkoppeite
Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Very Good
{110} very good, {011} and {110}
{110} very good, {011} and {110}
Fracture:
Step-Like
Density:
2.88(2) g/cm3 (Measured) 2.896 g/cm3 (Calculated)
Optical Data of Hartkoppeite
Type:
Biaxial (+)
RI values:
nα = 1.692(5) nβ = 1.693(5) nγ = 1.718(5)
2V:
Measured: 22° (1), Calculated: 22.9°
Max. Birefringence:
δ = 0.026
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
Pleochroism:
Non-pleochroic
Chemistry of Hartkoppeite
Mindat Formula:
Ca4Mn2+Mo6+6As5+4O32(OH)2(H2O)14 · 5H2O
Element Weights:
Crystallography of Hartkoppeite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 13.34610(15) Å, b = 13.53840(12) Å, c = 14.3087(2) Å
α = 71.080(5)°, β = 82.936(6)°, γ = 68.792(5)°
α = 71.080(5)°, β = 82.936(6)°, γ = 68.792(5)°
Ratio:
a:b:c = 0.986 : 1 : 1.057
Unit Cell V:
2,280.00 ų (Calculated from Unit Cell)
Z:
2
Twinning:
none
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.552 Å | (100) |
| 10.452 Å | (36) |
| 7.887 Å | (40) |
| 5.559 Å | (39) |
| 3.262 Å | (38) |
| 3.137 Å | (54) |
| 3.034 Å | (38) |
| 1.479 Å | (34) |
Locality:
Type Occurrence of Hartkoppeite
General Appearance of Type Material:
elongated and striated tabular crystals up to about 0.2 mm long. Tablets are flattened on {110}, elongated and striated parallel to [001], and exhibit the forms {110}, {1_10}, and {001}
Place of Conservation of Type Material:
Type material is deposited in the collections of the Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue number 77379
Geological Setting of Type Material:
Fuchs quarry exploits hydrothermal Mn-Fe-As-rich veins in a rhyolite body. A late-stage, low-temperature supergene mineral in an arsenic-rich vein.
Associated Minerals at Type Locality:
Synonyms of Hartkoppeite
Other Language Names for Hartkoppeite
Dutch:Hartkoppeiet
Related Minerals - Strunz-mindat Grouping
| 7.GB. | Stunorthropite | (NH4)4[Mo2O6(MoO4)2] |
| 7.GB. | Wangpuite | K3(PO4)(Mo12O36) |
| 7.GB. | Alexearlite | Hg3S2(MoO4) |
| 7.GB. | Ootannite | Th4+2W6+4O16 · 5H2O |
| 7.GB. | Natromolybdite | Na2MoO4 · 2H2O |
| 7.GB. | Marsaalamite-(Y) | Y(MoO4)(OH) |
| 7.GB.05 | Lindgrenite | Cu3(MoO4)2(OH)2 |
| 7.GB.10 | Szenicsite | Cu3(MoO4)(OH)4 |
| 7.GB.15 | 'UM1999-38-WO:CrV' | (V, Cr, W, O, H) [V:Cr:W ratio about 2:1:3] |
| 7.GB.15 | Huenite | Cu4(MoO4)3(OH)2 |
| 7.GB.15 | Cuprotungstite | Cu2(WO4)(OH)2 |
| 7.GB.20 | Phyllotungstite | (H2O,M)x(W,Fe)(O,OH)3 · yH2O (M = Ca, Cs, Pb or K) |
| 7.GB.25 | Rankachite | Ca0.5(V4+,V5+)(W6+,Fe3+)2O8(OH) · 2H2O |
| 7.GB.30 | Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| 7.GB.35 | Mpororoite | WAlO3(OH)3 · 2(H2O) |
| 7.GB.35 | Anthoinite | AlWO3(OH)3 |
| 7.GB.40 | Obradovicite-KCu | [K2(H2O)17Cu(H2O)6][Mo8As2Fe3+3O34(OH)3] |
| 7.GB.45 | Paramendozavilite | [KAl4(H2O)30][Mo12P6Fe3+6O60(OH)13] |
| 7.GB.45 | Mendozavilite-NaFe | [Na2(H2O)15Fe3+(H2O)6][Mo8P2Fe3+3O35(OH)2] |
| 7.GB.45 | Obradovicite-NaCu | Na2(H2O)17Cu(H2O)6][Mo8As2Fe3+3O34(OH)3] |
| 7.GB.45 | Obradovicite-NaNa | [Na2(H2O)16Na(H2O)6][Mo8As2Fe3+3O33(OH)4] |
| 7.GB.50 | Tancaite-(Ce) | FeCe(MoO4)3 · 3H2O |
| 7.GB.50 | Mendozavilite-NaCu | [Na2(H2O)15Cu(H2O)6][Mo8P2Fe3+3O34(OH)3] |
| 7.GB.50 | Mendozavilite-KCa | [K2(H2O)15Ca(H2O)6][Mo8P2Fe3+3O34(OH)3] |
| 7.GB.60 | Peterandresenite | Mn4Nb6O19 · 14H2O |
| 7.GB.60 | Hansesmarkite | Ca2Mn2Nb6O19 · 20H2O |
| 7.GB.60 | Melcherite | Ba2Na2Mg[Nb6O19] · 6H2O |
| 7.GB.65 | Ichnusaite | Th(MoO4)2 · 3H2O |
| 7.GB.70 | Markascherite | Cu3(MoO4)(OH)4 |
| 7.GB.75 | Nuragheite | Th(MoO4)2 · H2O |
| 7.GB.80 | Ophirite | Ca2Mg4[Zn2Mn3+2(H2O)2(Fe3+W9O34)2] · 46H2O |
Fluorescence of Hartkoppeite
none in long or short wave UV
Other Information
Notes:
At room temperature, the mineral is insoluble in H2O, but it is immediately soluble in 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 Hartkoppeite
mindat.org URL:
https://www.mindat.org/min-498758.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Hartkoppeite
Localities for Hartkoppeite
Showing 1 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.
Germany (TL) | |
| Bosi et al. (2025) +1 other reference |
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Fuchs Quarry, Hartkoppe, Sailauf, Aschaffenburg District, Lower Franconia, Bavaria, Germany