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Eyselite
A valid IMA mineral species
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Walter H. Eysel
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
IMA Classification of Eyselite
Approved
IMA Formula:
Fe3+Ge3O7(OH)
Approval year:
2003
First published:
2004
Classification of Eyselite
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 for Standard |
|---|---|---|
| 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
Chemistry of Eyselite
Mindat Formula:
Fe3+Ge4+3O7(OH)
Element Weights:
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:
Synonyms of Eyselite
Other Language Names for Eyselite
Related Minerals - Strunz-mindat Grouping
| 4.DM. | Sugarwhiteite | Pb2Te5O12 |
| 4.DM. | Zuolinite | Ba2Sr(Nb4.5Fe3+0.5)O15 |
| 4.DM. | Petfordite | ZrW6+2O7(OH)2(H2O)2 |
| 4.DM. | Bahariyaite | KMnO4 |
| 4.DM.05 | Rankamaite | (Na,K)3(Ta,Nb,Al)11(O,OH)31 |
| 4.DM.05 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 |
| 4.DM.15 | Cesplumtantite | (Cs,Na)2(Pb,Sb3+)3Ta8O24 |
| 4.DM.25 | Konzettite | CaMn4+Te6+O6 |
| 4.DM.25 | Kuranakhite | PbMn4+Te6+O6 |
| 4.DM.30 | Mambertiite | BiMo5+2.80O8(OH) |
| 4.DM.30 | Gelosaite | BiMo6+(2-5x)Mo5+6xO7(OH) · H2O |
| 4.DM.35 | Ekebergite | ThFeNb2O8 |
| 4.DM.45 | Riesite | TiO2 |
| 4.DM.50 | Sardignaite | BiMo2O7(OH) · 2H2O |
| 4.DM.55 | Tewite | (K1.5◻0.5)(Te1.25W0.25◻0.5)W5O19 |
| 4.DM.60 | Wumuite | K(W2.67Al0.33)O9 |
| 4.DM.60 | Kingsgateite | ZrMo6+2O7(OH)2 · 2H2O |
| 4.DM.60 | Morningstarite | Na(W2.67Fe3+0.33)O9 · H2O |
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
Localities for Eyselite
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.
Namibia (TL) | |
| Roberts et al. (2004) |
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