Eyselite
A valid IMA mineral species
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Formula:
Fe3+Ge4+3O7(OH)
Colour:
Dirty brown-yellow (aggregates) to yellow-tan (crystals)
Lustre:
Vitreous
Specific Gravity:
3.639 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of Walter Hans Eysel (1935, Langenselbold, Hesse, Germany – 23 October 1999, Heidelberg, Germany), Professor of Crystallography, Ruprecht-Karls-Universität, Heidelberg, Germany, for his contributions to the study of germanates and for his numerous contributions to the Powder Diffraction File.
This page provides mineralogical data about Eyselite.
Unique Identifiers
Mindat ID:
27221
Long-form identifier:
mindat:1:1:27221:4
GUID
(UUID V4):
(UUID V4):
eb5c4684-6d88-480f-ba01-c527d0bd4e00
Classification of Eyselite
Approved
Approval year:
2003
First published:
2004
Type description reference:
4.DM.20
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
M : With large (+- medium-sized) cations; unclassified
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
M : With large (+- 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 |
---|---|---|
Eys | 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 Eyselite
Vitreous
Transparency:
Transparent, Translucent, Opaque
Colour:
Dirty brown-yellow (aggregates) to yellow-tan (crystals)
Streak:
Brownish-yellow
Comment:
Soft
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
3.639 g/cm3 (Calculated)
Optical Data of Eyselite
Type:
Biaxial (+)
Anisotropism:
moderate
Pleochroism:
Non-pleochroic
Chemical Properties of Eyselite
Formula:
Fe3+Ge4+3O7(OH)
Elements listed:
Crystallography of Eyselite
Crystal System:
Orthorhombic
Cell Parameters:
a = 8.302 Å, b = 9.718 Å, c = 4.527 Å
Ratio:
a:b:c = 0.854 : 1 : 0.466
Unit Cell V:
365.2 ų
Z:
2
Morphology:
The type material shows the following forms: {100} major, very thin {010}, rounded {011}, and very thin rounded {001} minor. Crystals show growth steps on {100} and are partly hollow.
Comment:
Point Group: n.d.; Space Group: n.d. (P lattice) a
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
4.105 Å | (40) |
3.681 Å | (100) |
3.121 Å | (60b) |
2.921 Å | (100) |
2.512 Å | (40) |
2.403 Å | (90) |
1.646 Å | (80) |
1.624 Å | (50) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Eyselite
General Appearance of Type Material:
Individual subhedral to (rare) euhedral crystals are platy to very thin prismatic, elongate [001], with a length-to-width ratio of approximately 3:1 and not exceeding 20 µm in maximum length. Typical crystals are 20 × 14 × 1 µm in size.
Place of Conservation of Type Material:
Systematic Reference Series, National Mineral Collection, Geological Survey of Canada, Ottawa, Ontario, Canada, 68093.
Geological Setting of Type Material:
Very fine-grained aggregates in vugs of massive renierite – germanite – tennantite ore
Associated Minerals at Type Locality:
Reference:
Roberts, A.C., Seward, T.M., Reusser, E., Carpenter, G.J.C., Grice, J.D., Clark, S.M., Marcus. M.A. (2004) Eyselite, Fe3+Ge4+3O7(OH), a new mineral species from Tsumeb, Namibia. The Canadian Mineralogist: 42: 1771-1776.
Synonyms of Eyselite
Other Language Names for Eyselite
Related Minerals - Strunz-mindat Grouping
4.DM. | Bahariyaite | KMnO4 | Orth. mmm (2/m 2/m 2/m) : Pnma |
4.DM.05 | Rankamaite | (Na,K)3(Ta,Nb,Al)11(O,OH)31 | Orth. mmm (2/m 2/m 2/m) : Cmmm |
4.DM.05 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 | Orth. |
4.DM.15 | Cesplumtantite | (Cs,Na)2(Pb,Sb3+)3Ta8O24 | Tet. |
4.DM.25 | Kuranakhite | PbMn4+Te6+O6 | Orth. |
4.DM.30 | Gelosaite | BiMo6+(2-5x)Mo5+6xO7(OH) · H2O | Mon. 2/m : P21/m |
4.DM.30 | Mambertiite | BiMo5+2.80O8(OH) | Tric. 1 : P1 |
4.DM.35 | Ekebergite | ThFeNb2O8 | Mon. 2/m : P2/b |
4.DM.45 | Riesite | TiO2 | Mon. 2/m : P2/b |
4.DM.50 | Sardignaite | BiMo2O7(OH) · 2H2O | Mon. 2/m : P21/m |
4.DM.55 | Tewite | (K1.5◻0.5)(Te1.25W0.25◻0.5)W5O19 | Orth. mmm (2/m 2/m 2/m) : Pban |
4.DM.60 | Wumuite | KAl0.33W2.67O9 | Hex. 6/mmm (6/m 2/m 2/m) : P6/mmm |
4.DM.60 | Kingsgateite | ZrMo6+2O7(OH)2 · 2H2O | Tet. 4mm : I41cd |
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 Eyselite
mindat.org URL:
https://www.mindat.org/min-27221.html
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References for Eyselite
Reference List:
Localities for Eyselite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Namibia (TL) | |
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