Lindgrenite

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Lindgrenite
Lindgrenite-107037.jpg
Lindgrenite specimen from the San Samuel Mine of the Cachiyuyo de Llampos district, Copiapó Province, Atacama Region, Chile (field of view 4 mm)
General
Category Molybdate mineral
Formula Cu3(MoO4)2(OH)2
IMA symbol Lgr [1]
Strunz classification 7.GB.05
Dana classification 48.3.1.1
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/n
Unit cell a = 5.394, b = 14.023
c = 5.608 [Å]; β = 98.5°; Z = 2
Identification
ColorGreen to yellowish green
Crystal habit Tabular to platey crystals, may be acicular, massive or crust forming
Cleavage Perfect on {010} and {101}, poor on {100}
Fracture Micaceous
Tenacity Brittle
Mohs scale hardness4.5
Luster Greasey
Streak Pale green
Diaphaneity Transparent
Specific gravity 4.2
Optical propertiesBiaxial (-)
Refractive index nα = 1.930 nβ = 2.002 nγ = 2.020
Birefringence δ = 0.090
2V angle 71° (measured)
References [2] [3] [4]

Lindgrenite is an uncommon copper molybdate mineral with formula: Cu3(MoO4)2(OH)2. It occurs as tabular to platey monoclinic green to yellow green crystals.

Contents

Discovery and occurrence

It was first described in 1935 for an occurrence in the Chuquicamata Mine, Antofagasta, Chile, and named for Swedish–American economic geologist Waldemar Lindgren (1860–1939) of the Massachusetts Institute of Technology. [2] [3]

Lindgrenite occurs in the oxidized portions of copper–molybdenum bearing sulfide ore deposits. Associated minerals include antlerite, molybdenite, powellite, brochantite, chrysocolla, iron oxides and quartz. [2]

Lindgrenite in a quartz vug from the type locality of Chuquicamata (size: 1.7 x 1.7 x 1.4 cm) Lindgrenite-179398.jpg
Lindgrenite in a quartz vug from the type locality of Chuquicamata (size: 1.7 x 1.7 x 1.4 cm)
Lindgrenite, Inspiration mine, Arizona. Size 2 cm. Lindgrenite-445712.jpg
Lindgrenite, Inspiration mine, Arizona. Size 2 cm.

References

  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. 1 2 3 Lindgrenite in the Handbook of Mineralogy
  3. 1 2 Lindgrenite on Mindat.org
  4. Lindgrenite data on Webmineral

Further reading