Fairfieldite (Field of view 3 mm) Locality: Boca Rica claim, Sapucaia do Norte, Galiléia, Doce valley, Minas Gerais, Brazil Original description: White granular Lindbergite coating Frondelite matrix; Photo and collection Fernando Brederodes. — Photo: Fernando Brederodes · Public domain
Lindbergite
Lindbergite is an IMA-recognized mineral species in the organic mineral class, with the chemical formula Mn(C₂O₄)·2H₂O.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Humboldtine, Oxalate structural group.
Key properties: Mohs hardness 2.5; specific gravity 2.1; White streak; Vitreous luster; optically biaxial.
IMA symbol Ldb, IMA status: approved, named in 2003.
Found as a secondary mineral in granite pegmatites.
It is found associated with Triphylite, phosphosiderite, frondelite, strengite, cyrilovite, bermanite, rockbridgeite, huréaulite, tavorite, reddingite, heterosite, laueite.
The mineral was named to honor Marie Louise Lindberg (-Smith) (b. 1918), from the US Geological Survey, who described several new minerals from the nearby Sapucaia quarry (frondelite, faheyite.