Sky blue ammineite crystals (a mineral with amine groups, IMA 2008-032) in a matrix of halite. From: Pabellon de Pica, Chanabaya, Iquique Province, Tarapacá Region, Chile. — Photo: David Hospital · CC BY-SA 4.0
Ammineite
The first recognized mineral containing ammine groups, found in a Chilean guano deposit; several related ammine minerals were later found at the same site.
Intro adapted from Wikipedia (CC BY-SA).
Ammineite is an IMA-recognized mineral species in the organic mineral class, with the chemical formula CuCl₂·2NH₃.
It crystallizes in the orthorhombic crystal system (space group Cmcm).
Key properties: Mohs hardness 1; specific gravity 2.31; Light blue streak; Vitreous luster; optically biaxial.
IMA symbol Amm, IMA status: approved, named in 2008.
Likely the product of the interaction between NH3 from guano and Cu from chalcopyrite in underlying igneous rocks.
It is found associated with Halite, atacamite, salammoniac, darapskite.
Recognizes the first mineral described with ammine complex in its crystal structure.