Lindgrenite Locality: San Samuel Mine ("San Manuel Mine"), Carrera Pinto, Cachiyuyo de Llampos district, Copiapó Province, Atacama Region, Chile Field of view 4 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Lindgrenite
An uncommon green copper molybdate forming tabular monoclinic plates.
Intro adapted from Wikipedia (CC BY-SA).
Lindgrenite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu₃(Mo⁶⁺O₄)₂(OH)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 4.5; specific gravity 4.2; refractive index 1.984; optically biaxial.
IMA symbol Lgr, grandfathered status — known before the IMA’s founding, named in 1935.
Occurs as an uncommon secondary mineral in the oxidized zone of molybdenum-bearing copper deposits.
It is found associated with Antlerite, molybdenite, powellite, brochantite, chrysocolla, iron oxides, quartz.
The mineral was named to honor Professor Waldemar Lindgren (1860–1939), Swedish–American economic geologist, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.