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About DemesmaekeriteHide

Pb2Cu5(UO2)2(SeO3)6(OH)6 · 2H2O
Translucent green
3 - 4
Crystal System:
After Gaston Demesmaeker (Halle, Belgium March 5 1911 - ?), Belgian geologist, former director of the Union Minière du Haut Katanga (UMHK).
This page provides mineralogical data about Demesmaekerite.

Classification of DemesmaekeriteHide


4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
J : Selenites with additional anions, with H2O

7 : Hydrated Selenites, Tellurites and Sulfites containing Hydroxyl or Halogen

28 : Selenites, Selenates, Tellurites, and Tellurates
1 : Selenites

Physical Properties of DemesmaekeriteHide

Translucent green
3 - 4 on Mohs scale

Optical Data of DemesmaekeriteHide

Biaxial (+)
RI values:
nα = 1.835 nγ = 1.910
Max Birefringence:
δ = 0.075
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:

Chemical Properties of DemesmaekeriteHide

Pb2Cu5(UO2)2(SeO3)6(OH)6 · 2H2O
IMA Formula:
Pb2Cu5(UO2)2(Se4+O3)6(OH)6 · 2H2O

Crystallography of DemesmaekeriteHide

Crystal System:
Cell Parameters:
a = 11.94 Å, b = 10.02 Å, c = 5.62 Å
α = 90°, β = 100°, γ = 91.91°
a:b:c = 1.192 : 1 : 0.561
Unit Cell V:
661.78 ų (Calculated from Unit Cell)

Type Occurrence of DemesmaekeriteHide

Place of Conservation of Type Material:
Université de Paris
Musée de Minéralogie, Ecole des Mines de Paris
Muséum national d'Histoire naturelle, Paris
National History Museum, London

Synonyms of DemesmaekeriteHide

Other Language Names for DemesmaekeriteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
Malachite14 photos of Demesmaekerite associated with Malachite on
Derriksite8 photos of Demesmaekerite associated with Derriksite on
Chalcomenite8 photos of Demesmaekerite associated with Chalcomenite on
Guilleminite6 photos of Demesmaekerite associated with Guilleminite on
Kasolite4 photos of Demesmaekerite associated with Kasolite on
Digenite2 photos of Demesmaekerite associated with Digenite on
Vandenbrandeite2 photos of Demesmaekerite associated with Vandenbrandeite on
Trogtalite1 photo of Demesmaekerite associated with Trogtalite on
Cobaltomenite1 photo of Demesmaekerite associated with Cobaltomenite on
Marthozite1 photo of Demesmaekerite associated with Marthozite on

Related Minerals - Nickel-Strunz GroupingHide

4.JJ.05MarthoziteCu2+(UO2)3(SeO3)2O2 · 8H2OOrth.
4.JJ.10GuilleminiteBa(UO2)3(SeO3)2(OH)4 · 3H2OOrth. mm2 : Pmn21
4.JJ.15PiretiteCa(UO2)3(SeO3)2(OH)4 · 4H2OOrth.
4.JJ.25Haynesite(UO2)3(OH)2(SeO3)2 · 5H2OOrth.

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

28.1.1ChalcomeniteCuSeO3 · 2H2OOrth. 2 2 2 : P21 21 21
28.1.2ClinochalcomeniteCuSeO3 · 2H2OMon.
28.1.3FrancisiteCu3Bi(SeO3)2O2ClOrth. mmm (2/m 2/m 2/m) : Pmmn
28.1.6Haynesite(UO2)3(OH)2(SeO3)2 · 5H2OOrth.
28.1.8MarthoziteCu2+(UO2)3(SeO3)2O2 · 8H2OOrth.
28.1.9GuilleminiteBa(UO2)3(SeO3)2(OH)4 · 3H2OOrth. mm2 : Pmn21
28.1.11MandarinoiteFe3+2(SeO3)3 · 4H2OMon. 2/m : P21/b
28.1.12CobaltomeniteCoSeO3 · 2H2OMon.
28.1.13AhlfelditeNi(SeO3) · 2H2OMon. 2/m

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 DemesmaekeriteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
American Mineralogist: 51: 1815.
Ginderow, D. and Cesbron, F. (1983b) Structure de la demesmaekerite, Pb2Cu5(SeO3)6(UO2)2(OH)6·2H2O. Acta Crystallographica: C39: 824-827.
Burns, P.C. (2005) U 6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. Canadian Mineralogist: 43: 1839-1894.

Internet Links for DemesmaekeriteHide

Localities for DemesmaekeriteHide

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.
Czech Republic
  • Olomouc Region
    • Javorník (Jauernig)
Sejkora J., Škoda R., Pauliš P. 2006: Selenium mineralization of the uranium deposit Zálesí, Rychlebské Hory Mts., Czech Republic. Mineralogia Polonica - Special Papers, vol. 28, 196-198
Democratic Republic of the Congo (TL)
  • Katanga (Shaba)
    • Kolwezi District
      • Kolwezi (1965) 88, 422-425.; Wilson, W.E. (2018) The Musonoi mine, Kolwezi District, Lualaba Province, Democratic Republic of the Congo. Mineralogical Record 49: 236-304.;
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