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Walter H. Eysel
Dirty brown-yellow (aggregates) to yellow-tan (crystals)
Specific Gravity:
3.639 (Calculated)
Crystal System:
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.

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Classification of EyseliteHide

Approval year:
First published:

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

Physical Properties of EyseliteHide

Transparent, Translucent, Opaque
Dirty brown-yellow (aggregates) to yellow-tan (crystals)
3.639 g/cm3 (Calculated)

Optical Data of EyseliteHide

Biaxial (+)

Chemical Properties of EyseliteHide


Crystallography of EyseliteHide

Crystal System:
Cell Parameters:
a = 8.302 Å, b = 9.718 Å, c = 4.527 Å
a:b:c = 0.854 : 1 : 0.466
Unit Cell V:
365.2 ų
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.

X-Ray Powder DiffractionHide

Powder Diffraction Data:
4.105 Å(40)
3.681 Å(100)
3.121 Å(60b)
121) Å(
2.921 Å(100)
2.512 Å(40)
2.403 Å(90)
1.646 Å(80)
1.624 Å(50)

Type Occurrence of EyseliteHide

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:
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. Canadian Mineralogist: 42: 1771-1776.

Synonyms of EyseliteHide

Other Language Names for EyseliteHide

Simplified Chinese:埃塞尔石
Traditional Chinese:埃塞爾石

Related Minerals - Nickel-Strunz GroupingHide

4.DM.05Rankamaite(Na,K)3(Ta,Nb,Al)11(O,OH)31Orth. mmm (2/m 2/m 2/m) : Cmmm

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for EyseliteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
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. Canadian Mineralogist: 42: 1771-1776.

Internet Links for EyseliteHide

Localities for EyseliteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for 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 (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
Namibia (TL)
  • Oshikoto Region
    • Tsumeb
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.
Mineral and/or Locality  
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