Schmiederite Explained

Schmiederite
Category:Selenate minerals
Formula:Pb2Cu2(OH)4
Imasymbol:Scm[1]
Strunz:7.BC.65
System:Monoclinic
Class:Prismatic (2/m)
(same H-M symbol)
Symmetry:P21/m
Unit Cell:a = 9.92 Å, b = 5.71 Å
c = 9.36 Å; β = 101.86°; Z = 2
Color:Pale to deep Prussian blue
Habit:Fibrous in radial clusters; may be in crusts; powdery
Luster:Subadamantine to satiny
Streak:Light blue
Diaphaneity:Transparent
Gravity:5.62
Opticalprop:Biaxial (+)
Refractive:nα = 1.85–1.9 nβ = 1.9–1.95 nγ = 1.95–2.1
References:[2] [3] [4]

Schmiederite is a secondary mineral in the oxidized zone of selenium-bearing hydrothermal base metal deposits. Its chemical formula is Pb2Cu2(Se4+O3)(Se6+O4)(OH)4.[3] [4]

It was first described in 1962 for an occurrence in the Cóndor mine, Los Llantenes district, Sierra de Cacheuta, La Rioja Province, Argentina (type locality). It was named for Oscar Schmieder (1891–1980), German geographer.[3]

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. http://webmineral.com/data/Schmiederite.shtml Schmiederite on Webmineral
  3. http://www.mindat.org/min-3569.html Schmiederite on Mindat.org
  4. http://rruff.geo.arizona.edu/doclib/hom/schmiederite.pdf Handbook of Mineralogy