Lemanskiite Locality: El Guanaco Mine, Guanaco (Huanaco) , Santa Catalina , Antofagasta Province , Antofagasta Region , Chile ( Locality at mindat.org ) Field of view 10 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Lemanskiite
A blue copper-calcium arsenate-chloride from Chile's Abundancia mine — redefined in 2018 as a trihydrate distinct from lavendulan.
Intro adapted from Wikipedia (CC BY-SA).
Lemanskiite is an IMA-recognized mineral species in the arsenate class, with the chemical formula NaCaCu₅(AsO₄)₄Cl·3H₂O.
It crystallizes in the tetragonal crystal system (space group P4_122).
Key properties: Mohs hardness 2.5; specific gravity 3.78; Light blue streak; Vitreous luster; optically uniaxial.
IMA symbol Lmk, IMA status: approved, named in 1999.
A secondary mineral, as nodules or veinlets in gold-bearing quartz veins of a hydrothermal deposit.
It is found associated with Lammerite, olivenite, mansfieldite, senarmontite, a mineral of the crandallite group, rutile, anatase, talc. Lavendulan transforms easily to lemanskiite.
The mineral was named to honor Chester S. Lemanski, Jr. (b. 1947), New Jersey, USA, a mineral collector who first recognized this new mineral.