Pale blue takovite. Steve Sorrell collection. From Rocky's Reward Ni Mine, Leinster, Leonora Shire, Western Australia, Australia — Photo: Ralph Bottrill · CC BY 3.0
Takovite
Takovite is an IMA-recognized mineral species in the carbonate class, with the chemical formula Ni₆Al₂(CO₃)(OH)₁₆·4H₂O.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Hydrotalcite structural group.
Key properties: Mohs hardness 2; specific gravity 2.8; optically uniaxial.
IMA symbol Tkv, IMA status: approved, named in 1955.
Found in a karstitic bauxite at the contact of limestone and metamorphosed serpentinite (Takovo, Serbia); an alteration product of nickel sulfides (Western Australia).
It is found associated with Gibbsite, allophane (Takovo, Serbia); glaukosphaerite, népouite, gaspéite, paratacamite, nickeloan magnesite, gypsum, (Kambalda, Australia).
The name refers to Takovo, Serbia, from which it was first described.