Tsumcorite

Tsumcorite
Tsumcorite from the Tsumeb Mine, Namibia
General
CategoryArsenate minerals
Formula
(repeating unit)
PbZnFe2+(AsO4)2.H2O
IMA symbolTmc[1]
Strunz classification8.CG.15
Dana classification40.02.09.01
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupC2/m (no. 12)
Unit cella = 9.124 Å, b = 6.329 Å
c = 7.577 Å; β = 115.3°; Z = 2
Identification
Formula mass624.29 g/mol
ColorYellow-brown, red-brown, orange
Crystal habitRadiating, fibrous crusts
TwinningCommon, on an unknown law
CleavageGood on {001}
Mohs scale hardness4+12
LusterVitreous
StreakYellow
DiaphaneityTranslucent
Specific gravity5.2
Optical propertiesBiaxial
Refractive indexnα = 1.87–1.91 nβ = 1.89–1.93 nγ = 1.92–1.96
PleochroismWeak, yellow to yellow-green
2V angle67–83.5°
SolubilityDissolves in HCl
References[2][3][4][5][6][7]

Tsumcorite is a rare hydrated lead arsenate mineral that was discovered in 1971, and reported by Geier, Kautz and Muller.[6] It was named after the TSUMeb CORporation mine at Tsumeb, in Namibia, in recognition of the Corporation's support for mineralogical investigations of the orebody at its Mineral Research Laboratory.[5]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Gaines et al (1997) Dana’s New Mineralogy Eighth Edition. Wiley
  3. ^ Mindat.org
  4. ^ Webmineral data
  5. ^ a b Handbook of Mineralogy
  6. ^ a b Fleischer M (1972) New mineral names, American Mineralogist 57, 1558, being a summary of Geier, Kautz and Muller (1971) Neues Jahrbuch für Mineralogie (Monatshefte) 1971: 304–309
  7. ^ Tillmanns, E.; Gebert, W. (1 December 1973). "The crystal structure of tsumcorite, a new mineral from the Tsumeb mine, S. W. Africa". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 29 (12): 2789–2794. doi:10.1107/S0567740873007545.